commit 6577e0cbea9d8572e4dede283355bc17dc803676 Author: Arjun Patel Date: Wed Feb 20 15:09:59 2019 -0800 Initial commit diff --git a/.gitattributes b/.gitattributes new file mode 100644 index 0000000..dfe0770 --- /dev/null +++ b/.gitattributes @@ -0,0 +1,2 @@ +# Auto detect text files and perform LF normalization +* text=auto diff --git a/.vscode/settings.json b/.vscode/settings.json new file mode 100644 index 0000000..6445272 --- /dev/null +++ b/.vscode/settings.json @@ -0,0 +1,3 @@ +{ + "python.pythonPath": "C:\\Users\\talksik\\Anaconda3\\envs\\cs188\\python.exe" +} \ No newline at end of file diff --git a/python_basics/foreach.py b/python_basics/foreach.py new file mode 100644 index 0000000..936bd45 --- /dev/null +++ b/python_basics/foreach.py @@ -0,0 +1,11 @@ +# This is what a comment looks like +fruits = ['apples', 'oranges', 'pears', 'bananas'] +for fruit in fruits: + print(fruit + ' for sale') + +fruitPrices = {'apples': 2.00, 'oranges': 1.50, 'pears': 1.75} +for fruit, price in fruitPrices.items(): + if price < 2.00: + print('%s cost %f a pound' % (fruit, price)) + else: + print(fruit + ' are too expensive!') diff --git a/python_basics/helloWorld.py b/python_basics/helloWorld.py new file mode 100644 index 0000000..e4904dd --- /dev/null +++ b/python_basics/helloWorld.py @@ -0,0 +1,3 @@ +# Comment: This is a fairly simple Python script + +print('Hello, World!') diff --git a/python_basics/listcomp.py b/python_basics/listcomp.py new file mode 100644 index 0000000..dc85a2a --- /dev/null +++ b/python_basics/listcomp.py @@ -0,0 +1,5 @@ +nums = [1, 2, 3, 4, 5, 6] +oddNums = [x for x in nums if x % 2 == 1] +print(oddNums) +oddNumsPlusOne = [x + 1 for x in nums if x % 2 == 1] +print(oddNumsPlusOne) diff --git a/python_basics/listcomp2.py b/python_basics/listcomp2.py new file mode 100644 index 0000000..e4f159c --- /dev/null +++ b/python_basics/listcomp2.py @@ -0,0 +1,2 @@ +strings = ['Some string', 'Art', 'Music', 'Artificial Intelligence'] +print([x.lower() for x in strings if len(x) > 5]) diff --git a/python_basics/quickSort.py b/python_basics/quickSort.py new file mode 100644 index 0000000..341997d --- /dev/null +++ b/python_basics/quickSort.py @@ -0,0 +1,12 @@ +def quickSort(lst): + if len(lst) <= 1: + return lst + smaller = [x for x in lst[1:] if x < lst[0]] + larger = [x for x in lst[1:] if x >= lst[0]] + return quickSort(smaller) + [lst[0]] + quickSort(larger) + + +# Main Function +if __name__ == '__main__': + lst = [2, 4, 5, 1] + print(quickSort(lst)) diff --git a/python_basics/quicksort_try.py b/python_basics/quicksort_try.py new file mode 100644 index 0000000..cb3abd6 --- /dev/null +++ b/python_basics/quicksort_try.py @@ -0,0 +1,5 @@ +def quicksort(arr): + pivot = arr[0] + for item in arr[1:]: + if item > pivot: + \ No newline at end of file diff --git a/python_basics/shop.py b/python_basics/shop.py new file mode 100644 index 0000000..d48f8f0 --- /dev/null +++ b/python_basics/shop.py @@ -0,0 +1,43 @@ +class FruitShop: + + def __init__(self, name, fruitPrices): + """ + name: Name of the fruit shop + + fruitPrices: Dictionary with keys as fruit + strings and prices for values e.g. + {'apples':2.00, 'oranges': 1.50, 'pears': 1.75} + """ + self.fruitPrices = fruitPrices + self.name = name + print('Welcome to %s fruit shop' % (name)) + + def getCostPerPound(self, fruit): + """ + fruit: Fruit string + Returns cost of 'fruit', assuming 'fruit' + is in our inventory or None otherwise + """ + if fruit not in self.fruitPrices: + print("Sorry we don't have %s" % (fruit)) + return None + return self.fruitPrices[fruit] + + def getPriceOfOrder(self, orderList): + """ + orderList: List of (fruit, numPounds) tuples + + Returns cost of orderList. If any of the fruit are + """ + totalCost = 0.0 + for fruit, numPounds in orderList: + costPerPound = self.getCostPerPound(fruit) + if costPerPound != None: + totalCost += numPounds * costPerPound + return totalCost + + def getName(self): + return self.name + + def __str__(self): + return "" % self.getName() diff --git a/python_basics/shopTest.py b/python_basics/shopTest.py new file mode 100644 index 0000000..5d934e5 --- /dev/null +++ b/python_basics/shopTest.py @@ -0,0 +1,16 @@ +import shop + +shopName = 'the Berkeley Bowl' +fruitPrices = {'apples': 1.00, 'oranges': 1.50, 'pears': 1.75} +berkeleyShop = shop.FruitShop(shopName, fruitPrices) +applePrice = berkeleyShop.getCostPerPound('apples') +print(applePrice) +print('Apples cost $%.2f at %s.' % (applePrice, shopName)) + +otherName = 'the Stanford Mall' +otherFruitPrices = {'kiwis': 6.00, 'apples': 4.50, 'peaches': 8.75} +otherFruitShop = shop.FruitShop(otherName, otherFruitPrices) +otherPrice = otherFruitShop.getCostPerPound('apples') +print(otherPrice) +print('Apples cost $%.2f at %s.' % (otherPrice, otherName)) +print("My, that's expensive!") diff --git a/tutorial/__pycache__/addition.cpython-36.pyc b/tutorial/__pycache__/addition.cpython-36.pyc new file mode 100644 index 0000000..f526a12 Binary files /dev/null and b/tutorial/__pycache__/addition.cpython-36.pyc differ diff --git a/tutorial/__pycache__/buyLotsOfFruit.cpython-36.pyc b/tutorial/__pycache__/buyLotsOfFruit.cpython-36.pyc new file mode 100644 index 0000000..5646ec4 Binary files /dev/null and b/tutorial/__pycache__/buyLotsOfFruit.cpython-36.pyc differ diff --git a/tutorial/__pycache__/grading.cpython-36.pyc b/tutorial/__pycache__/grading.cpython-36.pyc new file mode 100644 index 0000000..de53023 Binary files /dev/null and b/tutorial/__pycache__/grading.cpython-36.pyc differ diff --git a/tutorial/__pycache__/projectParams.cpython-36.pyc b/tutorial/__pycache__/projectParams.cpython-36.pyc new file mode 100644 index 0000000..6c27d77 Binary files /dev/null and b/tutorial/__pycache__/projectParams.cpython-36.pyc differ diff --git a/tutorial/__pycache__/shop.cpython-36.pyc b/tutorial/__pycache__/shop.cpython-36.pyc new file mode 100644 index 0000000..ca1afed Binary files /dev/null and b/tutorial/__pycache__/shop.cpython-36.pyc differ diff --git a/tutorial/__pycache__/shopAroundTown.cpython-36.pyc b/tutorial/__pycache__/shopAroundTown.cpython-36.pyc new file mode 100644 index 0000000..4c7c12d Binary files /dev/null and b/tutorial/__pycache__/shopAroundTown.cpython-36.pyc differ diff --git a/tutorial/__pycache__/shopSmart.cpython-36.pyc b/tutorial/__pycache__/shopSmart.cpython-36.pyc new file mode 100644 index 0000000..b9943ab Binary files /dev/null and b/tutorial/__pycache__/shopSmart.cpython-36.pyc differ diff --git a/tutorial/__pycache__/testClasses.cpython-36.pyc b/tutorial/__pycache__/testClasses.cpython-36.pyc new file mode 100644 index 0000000..da868e7 Binary files /dev/null and b/tutorial/__pycache__/testClasses.cpython-36.pyc differ diff --git a/tutorial/__pycache__/testParser.cpython-36.pyc b/tutorial/__pycache__/testParser.cpython-36.pyc new file mode 100644 index 0000000..5a92825 Binary files /dev/null and b/tutorial/__pycache__/testParser.cpython-36.pyc differ diff --git a/tutorial/__pycache__/textDisplay.cpython-36.pyc b/tutorial/__pycache__/textDisplay.cpython-36.pyc new file mode 100644 index 0000000..c3e3bf9 Binary files /dev/null and b/tutorial/__pycache__/textDisplay.cpython-36.pyc differ diff --git a/tutorial/__pycache__/town.cpython-36.pyc b/tutorial/__pycache__/town.cpython-36.pyc new file mode 100644 index 0000000..387b6a3 Binary files /dev/null and b/tutorial/__pycache__/town.cpython-36.pyc differ diff --git a/tutorial/__pycache__/tutorialTestClasses.cpython-36.pyc b/tutorial/__pycache__/tutorialTestClasses.cpython-36.pyc new file mode 100644 index 0000000..007212e Binary files /dev/null and b/tutorial/__pycache__/tutorialTestClasses.cpython-36.pyc differ diff --git a/tutorial/__pycache__/util.cpython-36.pyc b/tutorial/__pycache__/util.cpython-36.pyc new file mode 100644 index 0000000..50361c4 Binary files /dev/null and b/tutorial/__pycache__/util.cpython-36.pyc differ diff --git a/tutorial/addition.py b/tutorial/addition.py new file mode 100644 index 0000000..5013ac1 --- /dev/null +++ b/tutorial/addition.py @@ -0,0 +1,23 @@ +# addition.py +# ----------- +# Licensing Information: You are free to use or extend these projects for +# educational purposes provided that (1) you do not distribute or publish +# solutions, (2) you retain this notice, and (3) you provide clear +# attribution to UC Berkeley, including a link to http://ai.berkeley.edu. +# +# Attribution Information: The Pacman AI projects were developed at UC Berkeley. +# The core projects and autograders were primarily created by John DeNero +# (denero@cs.berkeley.edu) and Dan Klein (klein@cs.berkeley.edu). +# Student side autograding was added by Brad Miller, Nick Hay, and +# Pieter Abbeel (pabbeel@cs.berkeley.edu). + + +""" +Run python autograder.py +""" + + +def add(a, b): + "Return the sum of a and b" + print("Passed a=%s and b=%s, returning a+b=%s" % (a,b,a+b)) + return a+b \ No newline at end of file diff --git a/tutorial/autograder.py b/tutorial/autograder.py new file mode 100644 index 0000000..0f339a8 --- /dev/null +++ b/tutorial/autograder.py @@ -0,0 +1,359 @@ +# autograder.py +# ------------- +# Licensing Information: You are free to use or extend these projects for +# educational purposes provided that (1) you do not distribute or publish +# solutions, (2) you retain this notice, and (3) you provide clear +# attribution to UC Berkeley, including a link to http://ai.berkeley.edu. +# +# Attribution Information: The Pacman AI projects were developed at UC Berkeley. +# The core projects and autograders were primarily created by John DeNero +# (denero@cs.berkeley.edu) and Dan Klein (klein@cs.berkeley.edu). +# Student side autograding was added by Brad Miller, Nick Hay, and +# Pieter Abbeel (pabbeel@cs.berkeley.edu). + + +# imports from python standard library +from __future__ import print_function +import grading +import imp +import optparse +import os +import re +import sys +import projectParams +import random +random.seed(0) +try: + from pacman import GameState +except: + pass + +# register arguments and set default values +def readCommand(argv): + parser = optparse.OptionParser(description = 'Run public tests on student code') + parser.set_defaults(generateSolutions=False, edxOutput=False, gsOutput=False, muteOutput=False, printTestCase=False, noGraphics=False) + parser.add_option('--test-directory', + dest = 'testRoot', + default = 'test_cases', + help = 'Root test directory which contains subdirectories corresponding to each question') + parser.add_option('--student-code', + dest = 'studentCode', + default = projectParams.STUDENT_CODE_DEFAULT, + help = 'comma separated list of student code files') + parser.add_option('--code-directory', + dest = 'codeRoot', + default = "", + help = 'Root directory containing the student and testClass code') + parser.add_option('--test-case-code', + dest = 'testCaseCode', + default = projectParams.PROJECT_TEST_CLASSES, + help = 'class containing testClass classes for this project') + parser.add_option('--generate-solutions', + dest = 'generateSolutions', + action = 'store_true', + help = 'Write solutions generated to .solution file') + parser.add_option('--edx-output', + dest = 'edxOutput', + action = 'store_true', + help = 'Generate edX output files') + parser.add_option('--gradescope-output', + dest = 'gsOutput', + action = 'store_true', + help = 'Generate GradeScope output files') + parser.add_option('--mute', + dest = 'muteOutput', + action = 'store_true', + help = 'Mute output from executing tests') + parser.add_option('--print-tests', '-p', + dest = 'printTestCase', + action = 'store_true', + help = 'Print each test case before running them.') + parser.add_option('--test', '-t', + dest = 'runTest', + default = None, + help = 'Run one particular test. Relative to test root.') + parser.add_option('--question', '-q', + dest = 'gradeQuestion', + default = None, + help = 'Grade one particular question.') + parser.add_option('--no-graphics', + dest = 'noGraphics', + action = 'store_true', + help = 'No graphics display for pacman games.') + (options, args) = parser.parse_args(argv) + return options + + +# confirm we should author solution files +def confirmGenerate(): + print('WARNING: this action will overwrite any solution files.') + print('Are you sure you want to proceed? (yes/no)') + while True: + ans = sys.stdin.readline().strip() + if ans == 'yes': + break + elif ans == 'no': + sys.exit(0) + else: + print('please answer either "yes" or "no"') + + +# TODO: Fix this so that it tracebacks work correctly +# Looking at source of the traceback module, presuming it works +# the same as the intepreters, it uses co_filename. This is, +# however, a readonly attribute. +def setModuleName(module, filename): + functionType = type(confirmGenerate) + classType = type(optparse.Option) + + for i in dir(module): + o = getattr(module, i) + if hasattr(o, '__file__'): continue + + if type(o) == functionType: + setattr(o, '__file__', filename) + elif type(o) == classType: + setattr(o, '__file__', filename) + # TODO: assign member __file__'s? + #print i, type(o) + + +#from cStringIO import StringIO + +def loadModuleString(moduleSource): + # Below broken, imp doesn't believe its being passed a file: + # ValueError: load_module arg#2 should be a file or None + # + #f = StringIO(moduleCodeDict[k]) + #tmp = imp.load_module(k, f, k, (".py", "r", imp.PY_SOURCE)) + tmp = imp.new_module(k) + #exec moduleCodeDict[k] in tmp.__dict__ + setModuleName(tmp, k) + return tmp + +import py_compile + +def loadModuleFile(moduleName, filePath): + with open(filePath, 'r') as f: + return imp.load_module(moduleName, f, "%s.py" % moduleName, (".py", "r", imp.PY_SOURCE)) + + +def readFile(path, root=""): + "Read file from disk at specified path and return as string" + with open(os.path.join(root, path), 'r') as handle: + return handle.read() + + +####################################################################### +# Error Hint Map +####################################################################### + +# TODO: use these +ERROR_HINT_MAP = { + 'q1': { + "": """ + We noticed that your project threw an IndexError on q1. + While many things may cause this, it may have been from + assuming a certain number of successors from a state space + or assuming a certain number of actions available from a given + state. Try making your code more general (no hardcoded indices) + and submit again! + """ + }, + 'q3': { + "": """ + We noticed that your project threw an AttributeError on q3. + While many things may cause this, it may have been from assuming + a certain size or structure to the state space. For example, if you have + a line of code assuming that the state is (x, y) and we run your code + on a state space with (x, y, z), this error could be thrown. Try + making your code more general and submit again! + + """ + } +} + +import pprint + +def splitStrings(d): + d2 = dict(d) + for k in d: + if k[0:2] == "__": + del d2[k] + continue + if d2[k].find("\n") >= 0: + d2[k] = d2[k].split("\n") + return d2 + + +def printTest(testDict, solutionDict): + pp = pprint.PrettyPrinter(indent=4) + print("Test case:") + for line in testDict["__raw_lines__"]: + print(" |", line) + print("Solution:") + for line in solutionDict["__raw_lines__"]: + print(" |", line) + + +def runTest(testName, moduleDict, printTestCase=False, display=None): + import testParser + import testClasses + for module in moduleDict: + setattr(sys.modules[__name__], module, moduleDict[module]) + + testDict = testParser.TestParser(testName + ".test").parse() + solutionDict = testParser.TestParser(testName + ".solution").parse() + test_out_file = os.path.join('%s.test_output' % testName) + testDict['test_out_file'] = test_out_file + testClass = getattr(projectTestClasses, testDict['class']) + + questionClass = getattr(testClasses, 'Question') + question = questionClass({'max_points': 0}, display) + testCase = testClass(question, testDict) + + if printTestCase: + printTest(testDict, solutionDict) + + # This is a fragile hack to create a stub grades object + grades = grading.Grades(projectParams.PROJECT_NAME, [(None,0)]) + testCase.execute(grades, moduleDict, solutionDict) + + +# returns all the tests you need to run in order to run question +def getDepends(testParser, testRoot, question): + allDeps = [question] + questionDict = testParser.TestParser(os.path.join(testRoot, question, 'CONFIG')).parse() + if 'depends' in questionDict: + depends = questionDict['depends'].split() + for d in depends: + # run dependencies first + allDeps = getDepends(testParser, testRoot, d) + allDeps + return allDeps + +# get list of questions to grade +def getTestSubdirs(testParser, testRoot, questionToGrade): + problemDict = testParser.TestParser(os.path.join(testRoot, 'CONFIG')).parse() + if questionToGrade != None: + questions = getDepends(testParser, testRoot, questionToGrade) + if len(questions) > 1: + print('Note: due to dependencies, the following tests will be run: %s' % ' '.join(questions)) + return questions + if 'order' in problemDict: + return problemDict['order'].split() + return sorted(os.listdir(testRoot)) + + +# evaluate student code +def evaluate(generateSolutions, testRoot, moduleDict, exceptionMap=ERROR_HINT_MAP, + edxOutput=False, muteOutput=False, gsOutput=False, + printTestCase=False, questionToGrade=None, display=None): + # imports of testbench code. note that the testClasses import must follow + # the import of student code due to dependencies + import testParser + import testClasses + for module in moduleDict: + setattr(sys.modules[__name__], module, moduleDict[module]) + + questions = [] + questionDicts = {} + test_subdirs = getTestSubdirs(testParser, testRoot, questionToGrade) + for q in test_subdirs: + subdir_path = os.path.join(testRoot, q) + if not os.path.isdir(subdir_path) or q[0] == '.': + continue + + # create a question object + questionDict = testParser.TestParser(os.path.join(subdir_path, 'CONFIG')).parse() + questionClass = getattr(testClasses, questionDict['class']) + question = questionClass(questionDict, display) + questionDicts[q] = questionDict + + # load test cases into question + tests = filter(lambda t: re.match('[^#~.].*\.test\Z', t), os.listdir(subdir_path)) + tests = map(lambda t: re.match('(.*)\.test\Z', t).group(1), tests) + for t in sorted(tests): + test_file = os.path.join(subdir_path, '%s.test' % t) + solution_file = os.path.join(subdir_path, '%s.solution' % t) + test_out_file = os.path.join(subdir_path, '%s.test_output' % t) + testDict = testParser.TestParser(test_file).parse() + if testDict.get("disabled", "false").lower() == "true": + continue + testDict['test_out_file'] = test_out_file + testClass = getattr(projectTestClasses, testDict['class']) + testCase = testClass(question, testDict) + def makefun(testCase, solution_file): + if generateSolutions: + # write solution file to disk + return lambda grades: testCase.writeSolution(moduleDict, solution_file) + else: + # read in solution dictionary and pass as an argument + testDict = testParser.TestParser(test_file).parse() + solutionDict = testParser.TestParser(solution_file).parse() + if printTestCase: + return lambda grades: printTest(testDict, solutionDict) or testCase.execute(grades, moduleDict, solutionDict) + else: + return lambda grades: testCase.execute(grades, moduleDict, solutionDict) + question.addTestCase(testCase, makefun(testCase, solution_file)) + + # Note extra function is necessary for scoping reasons + def makefun(question): + return lambda grades: question.execute(grades) + setattr(sys.modules[__name__], q, makefun(question)) + questions.append((q, question.getMaxPoints())) + + grades = grading.Grades(projectParams.PROJECT_NAME, questions, + gsOutput=gsOutput, edxOutput=edxOutput, muteOutput=muteOutput) + if questionToGrade == None: + for q in questionDicts: + for prereq in questionDicts[q].get('depends', '').split(): + grades.addPrereq(q, prereq) + + grades.grade(sys.modules[__name__], bonusPic = projectParams.BONUS_PIC) + return grades.points + + + +def getDisplay(graphicsByDefault, options=None): + graphics = graphicsByDefault + if options is not None and options.noGraphics: + graphics = False + if graphics: + try: + import graphicsDisplay + return graphicsDisplay.PacmanGraphics(1, frameTime=.05) + except ImportError: + pass + import textDisplay + return textDisplay.NullGraphics() + + + + +if __name__ == '__main__': + options = readCommand(sys.argv) + if options.generateSolutions: + confirmGenerate() + codePaths = options.studentCode.split(',') + # moduleCodeDict = {} + # for cp in codePaths: + # moduleName = re.match('.*?([^/]*)\.py', cp).group(1) + # moduleCodeDict[moduleName] = readFile(cp, root=options.codeRoot) + # moduleCodeDict['projectTestClasses'] = readFile(options.testCaseCode, root=options.codeRoot) + # moduleDict = loadModuleDict(moduleCodeDict) + + moduleDict = {} + for cp in codePaths: + moduleName = re.match('.*?([^/]*)\.py', cp).group(1) + moduleDict[moduleName] = loadModuleFile(moduleName, os.path.join(options.codeRoot, cp)) + moduleName = re.match('.*?([^/]*)\.py', options.testCaseCode).group(1) + moduleDict['projectTestClasses'] = loadModuleFile(moduleName, os.path.join(options.codeRoot, options.testCaseCode)) + + + if options.runTest != None: + runTest(options.runTest, moduleDict, printTestCase=options.printTestCase, display=getDisplay(True, options)) + else: + evaluate(options.generateSolutions, options.testRoot, moduleDict, + gsOutput=options.gsOutput, + edxOutput=options.edxOutput, muteOutput=options.muteOutput, printTestCase=options.printTestCase, + questionToGrade=options.gradeQuestion, display=getDisplay(options.gradeQuestion!=None, options)) diff --git a/tutorial/buyLotsOfFruit.py b/tutorial/buyLotsOfFruit.py new file mode 100644 index 0000000..2afc4e6 --- /dev/null +++ b/tutorial/buyLotsOfFruit.py @@ -0,0 +1,49 @@ +# buyLotsOfFruit.py +# ----------------- +# Licensing Information: You are free to use or extend these projects for +# educational purposes provided that (1) you do not distribute or publish +# solutions, (2) you retain this notice, and (3) you provide clear +# attribution to UC Berkeley, including a link to http://ai.berkeley.edu. +# +# Attribution Information: The Pacman AI projects were developed at UC Berkeley. +# The core projects and autograders were primarily created by John DeNero +# (denero@cs.berkeley.edu) and Dan Klein (klein@cs.berkeley.edu). +# Student side autograding was added by Brad Miller, Nick Hay, and +# Pieter Abbeel (pabbeel@cs.berkeley.edu). + + +""" +To run this script, type + + python buyLotsOfFruit.py + +Once you have correctly implemented the buyLotsOfFruit function, +the script should produce the output: + +Cost of [('apples', 2.0), ('pears', 3.0), ('limes', 4.0)] is 12.25 +""" +from __future__ import print_function + +fruitPrices = {'apples': 2.00, 'oranges': 1.50, 'pears': 1.75, + 'limes': 0.75, 'strawberries': 1.00} + + +def buyLotsOfFruit(orderList): + """ + orderList: List of (fruit, numPounds) tuples + + Returns cost of order + """ + totalCost = 0.0 + "*** YOUR CODE HERE ***" + for t in orderList: + item, pounds = t + totalCost += fruitPrices[item] * pounds + return totalCost + + +# Main Method +if __name__ == '__main__': + "This code runs when you invoke the script from the command line" + orderList = [('apples', 2.0), ('pears', 3.0), ('limes', 4.0)] + print('Cost of', orderList, 'is', buyLotsOfFruit(orderList)) diff --git a/tutorial/grading.py b/tutorial/grading.py new file mode 100644 index 0000000..edde8e3 --- /dev/null +++ b/tutorial/grading.py @@ -0,0 +1,322 @@ +# grading.py +# ---------- +# Licensing Information: You are free to use or extend these projects for +# educational purposes provided that (1) you do not distribute or publish +# solutions, (2) you retain this notice, and (3) you provide clear +# attribution to UC Berkeley, including a link to http://ai.berkeley.edu. +# +# Attribution Information: The Pacman AI projects were developed at UC Berkeley. +# The core projects and autograders were primarily created by John DeNero +# (denero@cs.berkeley.edu) and Dan Klein (klein@cs.berkeley.edu). +# Student side autograding was added by Brad Miller, Nick Hay, and +# Pieter Abbeel (pabbeel@cs.berkeley.edu). + + +"Common code for autograders" + +from __future__ import print_function +import cgi +import time +import sys +import json +import traceback +import pdb +from collections import defaultdict +import util + + +class Grades: + "A data structure for project grades, along with formatting code to display them" + + def __init__(self, projectName, questionsAndMaxesList, + gsOutput=False, edxOutput=False, muteOutput=False): + """ + Defines the grading scheme for a project + projectName: project name + questionsAndMaxesDict: a list of (question name, max points per question) + """ + self.questions = [el[0] for el in questionsAndMaxesList] + self.maxes = dict(questionsAndMaxesList) + self.points = Counter() + self.messages = dict([(q, []) for q in self.questions]) + self.project = projectName + self.start = time.localtime()[1:6] + self.sane = True # Sanity checks + self.currentQuestion = None # Which question we're grading + self.edxOutput = edxOutput + self.gsOutput = gsOutput # GradeScope output + self.mute = muteOutput + self.prereqs = defaultdict(set) + + # print 'Autograder transcript for %s' % self.project + print('Starting on %d-%d at %d:%02d:%02d' % self.start) + + def addPrereq(self, question, prereq): + self.prereqs[question].add(prereq) + + def grade(self, gradingModule, exceptionMap={}, bonusPic=False): + """ + Grades each question + gradingModule: the module with all the grading functions (pass in with sys.modules[__name__]) + """ + + completedQuestions = set([]) + for q in self.questions: + print('\nQuestion %s' % q) + print('=' * (9 + len(q))) + print() + self.currentQuestion = q + + incompleted = self.prereqs[q].difference(completedQuestions) + if len(incompleted) > 0: + prereq = incompleted.pop() + print( \ + """*** NOTE: Make sure to complete Question %s before working on Question %s, + *** because Question %s builds upon your answer for Question %s. + """ % (prereq, q, q, prereq)) + continue + + if self.mute: util.mutePrint() + try: + util.TimeoutFunction(getattr(gradingModule, q), 1800)(self) # Call the question's function + # TimeoutFunction(getattr(gradingModule, q),1200)(self) # Call the question's function + except Exception as inst: # originally, Exception, inst + self.addExceptionMessage(q, inst, traceback) + self.addErrorHints(exceptionMap, inst, q[1]) + except: + self.fail('FAIL: Terminated with a string exception.') + finally: + if self.mute: util.unmutePrint() + + if self.points[q] >= self.maxes[q]: + completedQuestions.add(q) + + print('\n### Question %s: %d/%d ###\n' % (q, self.points[q], self.maxes[q])) + + print('\nFinished at %d:%02d:%02d' % time.localtime()[3:6]) + print("\nProvisional grades\n==================") + + for q in self.questions: + print('Question %s: %d/%d' % (q, self.points[q], self.maxes[q])) + print('------------------') + print('Total: %d/%d' % (self.points.totalCount(), sum(self.maxes.values()))) + if bonusPic and self.points.totalCount() == 25: + print(""" + + ALL HAIL GRANDPAC. + LONG LIVE THE GHOSTBUSTING KING. + + --- ---- --- + | \ / + \ / | + | + \--/ \--/ + | + | + + | + | + + + | + @@@@@@@@@@@@@@@@@@@@@@@@@@ + @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ + @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ + @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ + \ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ + \ / @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ + V \ @@@@@@@@@@@@@@@@@@@@@@@@@@@@ + \ / @@@@@@@@@@@@@@@@@@@@@@@@@@ + V @@@@@@@@@@@@@@@@@@@@@@@@ + @@@@@@@@@@@@@@@@@@@@@@ + /\ @@@@@@@@@@@@@@@@@@@@@@ + / \ @@@@@@@@@@@@@@@@@@@@@@@@@ + /\ / @@@@@@@@@@@@@@@@@@@@@@@@@@@ + / \ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ + / @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ + @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ + @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ + @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ + @@@@@@@@@@@@@@@@@@@@@@@@@@ + @@@@@@@@@@@@@@@@@@ + +""") + print(""" +Your grades are NOT yet registered. To register your grades, make sure +to follow your instructor's guidelines to receive credit on your project. +""") + + if self.edxOutput: + self.produceOutput() + if self.gsOutput: + self.produceGradeScopeOutput() + + def addExceptionMessage(self, q, inst, traceback): + """ + Method to format the exception message, this is more complicated because + we need to cgi.escape the traceback but wrap the exception in a 
 tag
+        """
+        self.fail('FAIL: Exception raised: %s' % inst)
+        self.addMessage('')
+        for line in traceback.format_exc().split('\n'):
+            self.addMessage(line)
+
+    def addErrorHints(self, exceptionMap, errorInstance, questionNum):
+        typeOf = str(type(errorInstance))
+        questionName = 'q' + questionNum
+        errorHint = ''
+
+        # question specific error hints
+        if exceptionMap.get(questionName):
+            questionMap = exceptionMap.get(questionName)
+            if (questionMap.get(typeOf)):
+                errorHint = questionMap.get(typeOf)
+        # fall back to general error messages if a question specific
+        # one does not exist
+        if (exceptionMap.get(typeOf)):
+            errorHint = exceptionMap.get(typeOf)
+
+        # dont include the HTML if we have no error hint
+        if not errorHint:
+            return ''
+
+        for line in errorHint.split('\n'):
+            self.addMessage(line)
+
+    def produceGradeScopeOutput(self):
+        out_dct = {}
+
+        # total of entire submission
+        total_possible = sum(self.maxes.values())
+        total_score = sum(self.points.values())
+        out_dct['score'] = total_score
+        out_dct['max_score'] = total_possible
+        out_dct['output'] = "Total score (%d / %d)" % (total_score, total_possible)
+
+        # individual tests
+        tests_out = []
+        for name in self.questions:
+            test_out = {}
+            # test name
+            test_out['name'] = name
+            # test score
+            test_out['score'] = self.points[name]
+            test_out['max_score'] = self.maxes[name]
+            # others
+            is_correct = self.points[name] >= self.maxes[name]
+            test_out['output'] = "  Question {num} ({points}/{max}) {correct}".format(
+                num=(name[1] if len(name) == 2 else name),
+                points=test_out['score'],
+                max=test_out['max_score'],
+                correct=('X' if not is_correct else ''),
+            )
+            test_out['tags'] = []
+            tests_out.append(test_out)
+        out_dct['tests'] = tests_out
+
+        # file output
+        with open('gradescope_response.json', 'w') as outfile:
+            json.dump(out_dct, outfile)
+        return
+
+    def produceOutput(self):
+        edxOutput = open('edx_response.html', 'w')
+        edxOutput.write("
")
+
+        # first sum
+        total_possible = sum(self.maxes.values())
+        total_score = sum(self.points.values())
+        checkOrX = ''
+        if (total_score >= total_possible):
+            checkOrX = ''
+        header = """
+        

+            Total score ({total_score} / {total_possible})
+        

+    """.format(total_score=total_score,
+               total_possible=total_possible,
+               checkOrX=checkOrX
+               )
+        edxOutput.write(header)
+
+        for q in self.questions:
+            if len(q) == 2:
+                name = q[1]
+            else:
+                name = q
+            checkOrX = ''
+            if (self.points[q] >= self.maxes[q]):
+                checkOrX = ''
+            # messages = '\n
\n'.join(self.messages[q])
+            messages = "
%s
" % '\n'.join(self.messages[q])
+            output = """
+        

+          

+          

+            Question {q} ({points}/{max}) {checkOrX}
+          

+        

+          {messages}
+        

+        

+      

+      """.format(q=name,
+                 max=self.maxes[q],
+                 messages=messages,
+                 checkOrX=checkOrX,
+                 points=self.points[q]
+                 )
+            # print "*** output for Question %s " % q[1]
+            # print output
+            edxOutput.write(output)
+        edxOutput.write("
")
+        edxOutput.close()
+        edxOutput = open('edx_grade', 'w')
+        edxOutput.write(str(self.points.totalCount()))
+        edxOutput.close()
+
+    def fail(self, message, raw=False):
+        "Sets sanity check bit to false and outputs a message"
+        self.sane = False
+        self.assignZeroCredit()
+        self.addMessage(message, raw)
+
+    def assignZeroCredit(self):
+        self.points[self.currentQuestion] = 0
+
+    def addPoints(self, amt):
+        self.points[self.currentQuestion] += amt
+
+    def deductPoints(self, amt):
+        self.points[self.currentQuestion] -= amt
+
+    def assignFullCredit(self, message="", raw=False):
+        self.points[self.currentQuestion] = self.maxes[self.currentQuestion]
+        if message != "":
+            self.addMessage(message, raw)
+
+    def addMessage(self, message, raw=False):
+        if not raw:
+            # We assume raw messages, formatted for HTML, are printed separately
+            if self.mute: util.unmutePrint()
+            print('*** ' + message)
+            if self.mute: util.mutePrint()
+            message = cgi.escape(message)
+        self.messages[self.currentQuestion].append(message)
+
+    def addMessageToEmail(self, message):
+        print("WARNING**** addMessageToEmail is deprecated %s" % message)
+        for line in message.split('\n'):
+            pass
+            # print '%%% ' + line + ' %%%'
+            # self.messages[self.currentQuestion].append(line)
+
+
+class Counter(dict):
+    """
+    Dict with default 0
+    """
+
+    def __getitem__(self, idx):
+        try:
+            return dict.__getitem__(self, idx)
+        except KeyError:
+            return 0
+
+    def totalCount(self):
+        """
+        Returns the sum of counts for all keys.
+        """
+        return sum(self.values())
diff --git a/tutorial/projectParams.py b/tutorial/projectParams.py
new file mode 100644
index 0000000..fa1a1ec
--- /dev/null
+++ b/tutorial/projectParams.py
@@ -0,0 +1,18 @@
+# projectParams.py
+# ----------------
+# Licensing Information:  You are free to use or extend these projects for
+# educational purposes provided that (1) you do not distribute or publish
+# solutions, (2) you retain this notice, and (3) you provide clear
+# attribution to UC Berkeley, including a link to http://ai.berkeley.edu.
+# 
+# Attribution Information: The Pacman AI projects were developed at UC Berkeley.
+# The core projects and autograders were primarily created by John DeNero
+# (denero@cs.berkeley.edu) and Dan Klein (klein@cs.berkeley.edu).
+# Student side autograding was added by Brad Miller, Nick Hay, and
+# Pieter Abbeel (pabbeel@cs.berkeley.edu).
+
+
+STUDENT_CODE_DEFAULT = 'addition.py,buyLotsOfFruit.py,shopSmart.py,shopAroundTown.py'
+PROJECT_TEST_CLASSES = 'tutorialTestClasses.py'
+PROJECT_NAME = 'Project 0: Tutorial'
+BONUS_PIC = False
diff --git a/tutorial/shop.py b/tutorial/shop.py
new file mode 100644
index 0000000..b4d604d
--- /dev/null
+++ b/tutorial/shop.py
@@ -0,0 +1,60 @@
+# shop.py
+# -------
+# Licensing Information:  You are free to use or extend these projects for
+# educational purposes provided that (1) you do not distribute or publish
+# solutions, (2) you retain this notice, and (3) you provide clear
+# attribution to UC Berkeley, including a link to http://ai.berkeley.edu.
+# 
+# Attribution Information: The Pacman AI projects were developed at UC Berkeley.
+# The core projects and autograders were primarily created by John DeNero
+# (denero@cs.berkeley.edu) and Dan Klein (klein@cs.berkeley.edu).
+# Student side autograding was added by Brad Miller, Nick Hay, and
+# Pieter Abbeel (pabbeel@cs.berkeley.edu).
+
+
+class FruitShop:
+
+    def __init__(self, name, fruitPrices):
+        """
+            name: Name of the fruit shop
+
+            fruitPrices: Dictionary with keys as fruit
+            strings and prices for values e.g.
+            {'apples':2.00, 'oranges': 1.50, 'pears': 1.75}
+        """
+        self.fruitPrices = fruitPrices
+        self.name = name
+        print('Welcome to %s fruit shop' % (name))
+
+    def getCostPerPound(self, fruit):
+        """
+            fruit: Fruit string
+        Returns cost of 'fruit', assuming 'fruit'
+        is in our inventory or None otherwise
+        """
+        if fruit not in self.fruitPrices:
+            return None
+        return self.fruitPrices[fruit]
+
+    def getPriceOfOrder(self, orderList):
+        """
+            orderList: List of (fruit, numPounds) tuples
+
+        Returns cost of orderList, only including the values of
+        fruits that this fruit shop has.
+        """
+        totalCost = 0.0
+        for fruit, numPounds in orderList:
+            costPerPound = self.getCostPerPound(fruit)
+            if costPerPound != None:
+                totalCost += numPounds * costPerPound
+        return totalCost
+
+    def getName(self):
+        return self.name
+
+    def __str__(self):
+        return "" % self.getName()
+
+    def __repr__(self):
+        return str(self)
diff --git a/tutorial/shopAroundTown.py b/tutorial/shopAroundTown.py
new file mode 100644
index 0000000..fd1a6c2
--- /dev/null
+++ b/tutorial/shopAroundTown.py
@@ -0,0 +1,114 @@
+# shopAroundTown.py
+# -----------------
+# Licensing Information:  You are free to use or extend these projects for
+# educational purposes provided that (1) you do not distribute or publish
+# solutions, (2) you retain this notice, and (3) you provide clear
+# attribution to UC Berkeley, including a link to http://ai.berkeley.edu.
+# 
+# Attribution Information: The Pacman AI projects were developed at UC Berkeley.
+# The core projects and autograders were primarily created by John DeNero
+# (denero@cs.berkeley.edu) and Dan Klein (klein@cs.berkeley.edu).
+# Student side autograding was added by Brad Miller, Nick Hay, and
+# Pieter Abbeel (pabbeel@cs.berkeley.edu).
+
+
+"""
+Here's the intended output of this script, once you fill it in:
+
+Welcome to shop1 fruit shop
+Welcome to shop2 fruit shop
+Welcome to shop3 fruit shop
+Orders: [('apples', 1.0), ('oranges', 3.0), ('limes', 2.0)]
+At gas price 1 the best route is: ['shop1', 'shop2', 'shop3']
+At gas price 3 the best route is: ['shop1', 'shop3']
+At gas price 5 the best route is: ['shop2']
+At gas price -1 the best route is: ['shop2', 'shop1', 'shop3']
+"""
+
+from __future__ import print_function
+import shop
+import town
+
+
+def shopAroundTown(orderList, fruitTown, gasCost):
+    """
+        orderList: List of (fruit, numPound) tuples
+        fruitTown: A Town object
+        gasCost: A number representing the cost of going one mile
+    Returns a list of shops in the order that is the optimal route to take when
+    buying the fruit in the orderList
+    """
+    possibleRoutes = []
+    subsets = getAllSubsets(fruitTown.getShops())
+    for subset in subsets:
+        names = [shop.getName() for shop in subset]
+        if fruitTown.allFruitsCarriedAtShops(orderList, names):
+            possibleRoutes += getAllPermutations(subset)
+    minCost, bestRoute = None, None
+    for route in possibleRoutes:
+        cost = fruitTown.getPriceOfOrderOnRoute(orderList, route, gasCost)
+        if minCost == None or cost < minCost:
+            minCost, bestRoute = cost, route
+    return bestRoute
+
+
+def getAllSubsets(lst):
+    """
+        lst: A list
+    Returns the powerset of lst, i.e. a list of all the possible subsets of lst
+    """
+    if not lst:
+        return []
+    withFirst = [[lst[0]] + rest for rest in getAllSubsets(lst[1:])]
+    withoutFirst = getAllSubsets(lst[1:])
+    return withFirst + withoutFirst
+
+
+def getAllPermutations(lst):
+    """
+        lst: A list
+    Returns a list of all permutations of lst
+    """
+    if not lst:
+        return []
+    elif len(lst) == 1:
+        return lst
+    allPermutations = []
+    for i in range(len(lst)):
+        item = lst[i]
+        withoutItem = lst[:i] + lst[i:]
+        allPermutations += prependToAll(item, getAllPermutations(withoutItem))
+    return allPermutations
+
+
+def prependToAll(item, lsts):
+    """
+        item: Any object
+        lsts: A list of lists
+    Returns a copy of lsts with item prepended to each list contained in lsts
+    """
+    return [[item] + lst for lst in lsts]
+
+
+if __name__ == '__main__':
+    "This code runs when you invoke the script from the command line"
+    orders = [('apples', 1.0), ('oranges', 3.0), ('limes', 2.0)]
+    dir1 = {'apples': 2.0, 'oranges': 1.0}
+    dir2 = {'apples': 1.0, 'oranges': 5.0, 'limes': 3.0}
+    dir3 = {'apples': 2.0, 'limes': 2.0}
+    shop1 = shop.FruitShop('shop1', dir1)
+    shop2 = shop.FruitShop('shop2', dir2)
+    shop3 = shop.FruitShop('shop3', dir3)
+    shops = [shop1, shop2, shop3]
+    distances = {('home', 'shop1'): 2,
+                 ('home', 'shop2'): 1,
+                 ('home', 'shop3'): 1,
+                 ('shop1', 'shop2'): 2.5,
+                 ('shop1', 'shop3'): 2.5,
+                 ('shop2', 'shop3'): 1
+                 }
+    fruitTown = town.Town(shops, distances)
+    print("Orders:", orders)
+    for price in (1, 3, 5, -1):
+        print("At gas price", price, "the best route is:", \
+              shopAroundTown(orders, fruitTown, price))
diff --git a/tutorial/shopSmart.py b/tutorial/shopSmart.py
new file mode 100644
index 0000000..b4323f8
--- /dev/null
+++ b/tutorial/shopSmart.py
@@ -0,0 +1,56 @@
+# shopSmart.py
+# ------------
+# Licensing Information:  You are free to use or extend these projects for
+# educational purposes provided that (1) you do not distribute or publish
+# solutions, (2) you retain this notice, and (3) you provide clear
+# attribution to UC Berkeley, including a link to http://ai.berkeley.edu.
+#
+# Attribution Information: The Pacman AI projects were developed at UC Berkeley.
+# The core projects and autograders were primarily created by John DeNero
+# (denero@cs.berkeley.edu) and Dan Klein (klein@cs.berkeley.edu).
+# Student side autograding was added by Brad Miller, Nick Hay, and
+# Pieter Abbeel (pabbeel@cs.berkeley.edu).
+
+
+"""
+Here's the intended output of this script, once you fill it in:
+
+Welcome to shop1 fruit shop
+Welcome to shop2 fruit shop
+For orders:  [('apples', 1.0), ('oranges', 3.0)] best shop is shop1
+For orders:  [('apples', 3.0)] best shop is shop2
+"""
+from __future__ import print_function
+import shop
+
+
+def shopSmart(orderList, fruitShops):
+    """
+        orderList: List of (fruit, numPound) tuples
+        fruitShops: List of FruitShops
+
+        Return the shop where order would be the least amount in total
+    """
+    "*** YOUR CODE HERE ***"
+    cheapest_shop, cheapest_order = fruitShops[0], fruitShops[0].getPriceOfOrder(
+        orderList)
+    for each_shop in fruitShops:
+        currOder = each_shop.getPriceOfOrder(orderList)
+        if currOder < cheapest_order:
+            cheapest_shop, cheapest_order = each_shop, currOder
+    return cheapest_shop
+
+
+if __name__ == '__main__':
+    "This code runs when you invoke the script from the command line"
+    orders = [('apples', 1.0), ('oranges', 3.0)]
+    dir1 = {'apples': 2.0, 'oranges': 1.0}
+    shop1 = shop.FruitShop('shop1', dir1)
+    dir2 = {'apples': 1.0, 'oranges': 5.0}
+    shop2 = shop.FruitShop('shop2', dir2)
+    shops = [shop1, shop2]
+    print("For orders ", orders, ", the best shop is",
+          shopSmart(orders, shops).getName())
+    orders = [('apples', 3.0)]
+    print("For orders: ", orders, ", the best shop is",
+          shopSmart(orders, shops).getName())
diff --git a/tutorial/testClasses.py b/tutorial/testClasses.py
new file mode 100644
index 0000000..7a4ce35
--- /dev/null
+++ b/tutorial/testClasses.py
@@ -0,0 +1,207 @@
+# testClasses.py
+# --------------
+# Licensing Information:  You are free to use or extend these projects for
+# educational purposes provided that (1) you do not distribute or publish
+# solutions, (2) you retain this notice, and (3) you provide clear
+# attribution to UC Berkeley, including a link to http://ai.berkeley.edu.
+# 
+# Attribution Information: The Pacman AI projects were developed at UC Berkeley.
+# The core projects and autograders were primarily created by John DeNero
+# (denero@cs.berkeley.edu) and Dan Klein (klein@cs.berkeley.edu).
+# Student side autograding was added by Brad Miller, Nick Hay, and
+# Pieter Abbeel (pabbeel@cs.berkeley.edu).
+
+
+# import modules from python standard library
+from __future__ import print_function
+import inspect
+import re
+import sys
+
+
+# Class which models a question in a project.  Note that questions have a
+# maximum number of points they are worth, and are composed of a series of
+# test cases
+class Question(object):
+
+    def raiseNotDefined(self):
+        print('Method not implemented: %s' % inspect.stack()[1][3])
+        sys.exit(1)
+
+    def __init__(self, questionDict, display):
+        self.maxPoints = int(questionDict['max_points'])
+        self.testCases = []
+        self.display = display
+
+    def getDisplay(self):
+        return self.display
+
+    def getMaxPoints(self):
+        return self.maxPoints
+
+    # Note that 'thunk' must be a function which accepts a single argument,
+    # namely a 'grading' object
+    def addTestCase(self, testCase, thunk):
+        self.testCases.append((testCase, thunk))
+
+    def execute(self, grades):
+        self.raiseNotDefined()
+
+
+# Question in which all test cases must be passed in order to receive credit
+class PassAllTestsQuestion(Question):
+
+    def execute(self, grades):
+        # TODO: is this the right way to use grades?  The autograder doesn't seem to use it.
+        testsFailed = False
+        grades.assignZeroCredit()
+        for _, f in self.testCases:
+            if not f(grades):
+                testsFailed = True
+        if testsFailed:
+            grades.fail("Tests failed.")
+        else:
+            grades.assignFullCredit()
+
+
+class ExtraCreditPassAllTestsQuestion(Question):
+    def __init__(self, questionDict, display):
+        Question.__init__(self, questionDict, display)
+        self.extraPoints = int(questionDict['extra_points'])
+
+    def execute(self, grades):
+        # TODO: is this the right way to use grades?  The autograder doesn't seem to use it.
+        testsFailed = False
+        grades.assignZeroCredit()
+        for _, f in self.testCases:
+            if not f(grades):
+                testsFailed = True
+        if testsFailed:
+            grades.fail("Tests failed.")
+        else:
+            grades.assignFullCredit()
+            grades.addPoints(self.extraPoints)
+
+
+# Question in which predict credit is given for test cases with a ``points'' property.
+# All other tests are mandatory and must be passed.
+class HackedPartialCreditQuestion(Question):
+
+    def execute(self, grades):
+        # TODO: is this the right way to use grades?  The autograder doesn't seem to use it.
+        grades.assignZeroCredit()
+
+        points = 0
+        passed = True
+        for testCase, f in self.testCases:
+            testResult = f(grades)
+            if "points" in testCase.testDict:
+                if testResult: points += float(testCase.testDict["points"])
+            else:
+                passed = passed and testResult
+
+        ## FIXME: Below terrible hack to match q3's logic
+        if int(points) == self.maxPoints and not passed:
+            grades.assignZeroCredit()
+        else:
+            grades.addPoints(int(points))
+
+
+class Q6PartialCreditQuestion(Question):
+    """Fails any test which returns False, otherwise doesn't effect the grades object.
+    Partial credit tests will add the required points."""
+
+    def execute(self, grades):
+        grades.assignZeroCredit()
+
+        results = []
+        for _, f in self.testCases:
+            results.append(f(grades))
+        if False in results:
+            grades.assignZeroCredit()
+
+
+class PartialCreditQuestion(Question):
+    """Fails any test which returns False, otherwise doesn't effect the grades object.
+    Partial credit tests will add the required points."""
+
+    def execute(self, grades):
+        grades.assignZeroCredit()
+
+        for _, f in self.testCases:
+            if not f(grades):
+                grades.assignZeroCredit()
+                grades.fail("Tests failed.")
+                return False
+
+
+class NumberPassedQuestion(Question):
+    """Grade is the number of test cases passed."""
+
+    def execute(self, grades):
+        grades.addPoints([f(grades) for _, f in self.testCases].count(True))
+
+
+# Template modeling a generic test case
+class TestCase(object):
+
+    def raiseNotDefined(self):
+        print('Method not implemented: %s' % inspect.stack()[1][3])
+        sys.exit(1)
+
+    def getPath(self):
+        return self.path
+
+    def __init__(self, question, testDict):
+        self.question = question
+        self.testDict = testDict
+        self.path = testDict['path']
+        self.messages = []
+
+    def __str__(self):
+        self.raiseNotDefined()
+
+    def execute(self, grades, moduleDict, solutionDict):
+        self.raiseNotDefined()
+
+    def writeSolution(self, moduleDict, filePath):
+        self.raiseNotDefined()
+        return True
+
+    # Tests should call the following messages for grading
+    # to ensure a uniform format for test output.
+    #
+    # TODO: this is hairy, but we need to fix grading.py's interface
+    # to get a nice hierarchical project - question - test structure,
+    # then these should be moved into Question proper.
+    def testPass(self, grades):
+        grades.addMessage('PASS: %s' % (self.path,))
+        for line in self.messages:
+            grades.addMessage('    %s' % (line,))
+        return True
+
+    def testFail(self, grades):
+        grades.addMessage('FAIL: %s' % (self.path,))
+        for line in self.messages:
+            grades.addMessage('    %s' % (line,))
+        return False
+
+    # This should really be question level?
+    #
+    def testPartial(self, grades, points, maxPoints):
+        grades.addPoints(points)
+        extraCredit = max(0, points - maxPoints)
+        regularCredit = points - extraCredit
+
+        grades.addMessage('%s: %s (%s of %s points)' % (
+            "PASS" if points >= maxPoints else "FAIL", self.path, regularCredit, maxPoints))
+        if extraCredit > 0:
+            grades.addMessage('EXTRA CREDIT: %s points' % (extraCredit,))
+
+        for line in self.messages:
+            grades.addMessage('    %s' % (line,))
+
+        return True
+
+    def addMessage(self, message):
+        self.messages.extend(message.split('\n'))
diff --git a/tutorial/testParser.py b/tutorial/testParser.py
new file mode 100644
index 0000000..15646d0
--- /dev/null
+++ b/tutorial/testParser.py
@@ -0,0 +1,86 @@
+# testParser.py
+# -------------
+# Licensing Information:  You are free to use or extend these projects for
+# educational purposes provided that (1) you do not distribute or publish
+# solutions, (2) you retain this notice, and (3) you provide clear
+# attribution to UC Berkeley, including a link to http://ai.berkeley.edu.
+# 
+# Attribution Information: The Pacman AI projects were developed at UC Berkeley.
+# The core projects and autograders were primarily created by John DeNero
+# (denero@cs.berkeley.edu) and Dan Klein (klein@cs.berkeley.edu).
+# Student side autograding was added by Brad Miller, Nick Hay, and
+# Pieter Abbeel (pabbeel@cs.berkeley.edu).
+
+from __future__ import print_function
+import re
+import sys
+
+
+class TestParser(object):
+
+    def __init__(self, path):
+        # save the path to the test file
+        self.path = path
+
+    def removeComments(self, rawlines):
+        # remove any portion of a line following a '#' symbol
+        fixed_lines = []
+        for l in rawlines:
+            idx = l.find('#')
+            if idx == -1:
+                fixed_lines.append(l)
+            else:
+                fixed_lines.append(l[0:idx])
+        return '\n'.join(fixed_lines)
+
+    def parse(self):
+        # read in the test case and remove comments
+        test = {}
+        with open(self.path) as handle:
+            raw_lines = handle.read().split('\n')
+
+        test_text = self.removeComments(raw_lines)
+        test['__raw_lines__'] = raw_lines
+        test['path'] = self.path
+        test['__emit__'] = []
+        lines = test_text.split('\n')
+        i = 0
+        # read a property in each loop cycle
+        while (i < len(lines)):
+            # skip blank lines
+            if re.match('\A\s*\Z', lines[i]):
+                test['__emit__'].append(("raw", raw_lines[i]))
+                i += 1
+                continue
+            m = re.match('\A([^"]*?):\s*"([^"]*)"\s*\Z', lines[i])
+            if m:
+                test[m.group(1)] = m.group(2)
+                test['__emit__'].append(("oneline", m.group(1)))
+                i += 1
+                continue
+            m = re.match('\A([^"]*?):\s*"""\s*\Z', lines[i])
+            if m:
+                msg = []
+                i += 1
+                while (not re.match('\A\s*"""\s*\Z', lines[i])):
+                    msg.append(raw_lines[i])
+                    i += 1
+                test[m.group(1)] = '\n'.join(msg)
+                test['__emit__'].append(("multiline", m.group(1)))
+                i += 1
+                continue
+            print('error parsing test file: %s' % self.path)
+            sys.exit(1)
+        return test
+
+
+def emitTestDict(testDict, handle):
+    for kind, data in testDict['__emit__']:
+        if kind == "raw":
+            handle.write(data + "\n")
+        elif kind == "oneline":
+            handle.write('%s: "%s"\n' % (data, testDict[data]))
+        elif kind == "multiline":
+            handle.write('%s: """\n%s\n"""\n' % (data, testDict[data]))
+        else:
+            raise Exception("Bad __emit__")
diff --git a/tutorial/test_cases/CONFIG b/tutorial/test_cases/CONFIG
new file mode 100644
index 0000000..eec8c0b
--- /dev/null
+++ b/tutorial/test_cases/CONFIG
@@ -0,0 +1 @@
+order: "q1 q2 q3"
diff --git a/tutorial/test_cases/q1/CONFIG b/tutorial/test_cases/q1/CONFIG
new file mode 100644
index 0000000..279f0f0
--- /dev/null
+++ b/tutorial/test_cases/q1/CONFIG
@@ -0,0 +1,2 @@
+max_points: "1"
+class: "PassAllTestsQuestion"
diff --git a/tutorial/test_cases/q1/addition1.solution b/tutorial/test_cases/q1/addition1.solution
new file mode 100644
index 0000000..6261975
--- /dev/null
+++ b/tutorial/test_cases/q1/addition1.solution
@@ -0,0 +1,3 @@
+# This is the solution file for test_cases/q1/addition1.test.
+# The result of evaluating the test must equal the below when cast to a string.
+result: "2"
diff --git a/tutorial/test_cases/q1/addition1.test b/tutorial/test_cases/q1/addition1.test
new file mode 100644
index 0000000..2d807c7
--- /dev/null
+++ b/tutorial/test_cases/q1/addition1.test
@@ -0,0 +1,7 @@
+class: "EvalTest"
+success: "add(a,b) returns the sum of a and b"
+failure: "add(a,b) must return the sum of a and b"
+
+# A python expression to be evaluated.  This expression must return the 
+# same result for the student and instructor's code.
+test: "addition.add(1,1)"
diff --git a/tutorial/test_cases/q1/addition2.solution b/tutorial/test_cases/q1/addition2.solution
new file mode 100644
index 0000000..49ebaa0
--- /dev/null
+++ b/tutorial/test_cases/q1/addition2.solution
@@ -0,0 +1,3 @@
+# This is the solution file for test_cases/q1/addition2.test.
+# The result of evaluating the test must equal the below when cast to a string.
+result: "5"
diff --git a/tutorial/test_cases/q1/addition2.test b/tutorial/test_cases/q1/addition2.test
new file mode 100644
index 0000000..76a0d91
--- /dev/null
+++ b/tutorial/test_cases/q1/addition2.test
@@ -0,0 +1,7 @@
+class: "EvalTest"
+success: "add(a,b) returns the sum of a and b"
+failure: "add(a,b) must return the sum of a and b"
+
+# A python expression to be evaluated.  This expression must return the 
+# same result for the student and instructor's code.
+test: "addition.add(2,3)"
diff --git a/tutorial/test_cases/q1/addition3.solution b/tutorial/test_cases/q1/addition3.solution
new file mode 100644
index 0000000..c258470
--- /dev/null
+++ b/tutorial/test_cases/q1/addition3.solution
@@ -0,0 +1,3 @@
+# This is the solution file for test_cases/q1/addition3.test.
+# The result of evaluating the test must equal the below when cast to a string.
+result: "7.9"
diff --git a/tutorial/test_cases/q1/addition3.test b/tutorial/test_cases/q1/addition3.test
new file mode 100644
index 0000000..462ff13
--- /dev/null
+++ b/tutorial/test_cases/q1/addition3.test
@@ -0,0 +1,7 @@
+class: "EvalTest"
+success: "add(a,b) returns the sum of a and b"
+failure: "add(a,b) must return the sum of a and b"
+
+# A python expression to be evaluated.  This expression must return the 
+# same result for the student and instructor's code.
+test: "addition.add(10,-2.1)"
diff --git a/tutorial/test_cases/q2/CONFIG b/tutorial/test_cases/q2/CONFIG
new file mode 100644
index 0000000..279f0f0
--- /dev/null
+++ b/tutorial/test_cases/q2/CONFIG
@@ -0,0 +1,2 @@
+max_points: "1"
+class: "PassAllTestsQuestion"
diff --git a/tutorial/test_cases/q2/food_price1.solution b/tutorial/test_cases/q2/food_price1.solution
new file mode 100644
index 0000000..b2a8e87
--- /dev/null
+++ b/tutorial/test_cases/q2/food_price1.solution
@@ -0,0 +1,3 @@
+# This is the solution file for test_cases/q2/food_price1.test.
+# The result of evaluating the test must equal the below when cast to a string.
+result: "12.25"
diff --git a/tutorial/test_cases/q2/food_price1.test b/tutorial/test_cases/q2/food_price1.test
new file mode 100644
index 0000000..93d2c3d
--- /dev/null
+++ b/tutorial/test_cases/q2/food_price1.test
@@ -0,0 +1,7 @@
+class: "EvalTest"
+success: "buyLotsOfFruit correctly computes the cost of the order"
+failure: "buyLotsOfFruit must compute the correct cost of the order"
+
+# A python expression to be evaluated.  This expression must return the 
+# same result for the student and instructor's code.
+test: "buyLotsOfFruit.buyLotsOfFruit([ ('apples', 2.0), ('pears',3.0), ('limes',4.0) ])"
diff --git a/tutorial/test_cases/q2/food_price2.solution b/tutorial/test_cases/q2/food_price2.solution
new file mode 100644
index 0000000..e3ec5e8
--- /dev/null
+++ b/tutorial/test_cases/q2/food_price2.solution
@@ -0,0 +1,3 @@
+# This is the solution file for test_cases/q2/food_price2.test.
+# The result of evaluating the test must equal the below when cast to a string.
+result: "14.75"
diff --git a/tutorial/test_cases/q2/food_price2.test b/tutorial/test_cases/q2/food_price2.test
new file mode 100644
index 0000000..b70e8d9
--- /dev/null
+++ b/tutorial/test_cases/q2/food_price2.test
@@ -0,0 +1,7 @@
+class: "EvalTest"
+success: "buyLotsOfFruit correctly computes the cost of the order"
+failure: "buyLotsOfFruit must compute the correct cost of the order"
+
+# A python expression to be evaluated.  This expression must return the 
+# same result for the student and instructor's code.
+test: "buyLotsOfFruit.buyLotsOfFruit([ ('apples', 4.0), ('pears',3.0), ('limes',2.0) ])"
diff --git a/tutorial/test_cases/q2/food_price3.solution b/tutorial/test_cases/q2/food_price3.solution
new file mode 100644
index 0000000..23976d6
--- /dev/null
+++ b/tutorial/test_cases/q2/food_price3.solution
@@ -0,0 +1,3 @@
+# This is the solution file for test_cases/q2/food_price3.test.
+# The result of evaluating the test must equal the below when cast to a string.
+result: "6.4375"
diff --git a/tutorial/test_cases/q2/food_price3.test b/tutorial/test_cases/q2/food_price3.test
new file mode 100644
index 0000000..9d9a395
--- /dev/null
+++ b/tutorial/test_cases/q2/food_price3.test
@@ -0,0 +1,7 @@
+class: "EvalTest"
+success: "buyLotsOfFruit correctly computes the cost of the order"
+failure: "buyLotsOfFruit must compute the correct cost of the order"
+
+# A python expression to be evaluated.  This expression must return the 
+# same result for the student and instructor's code.
+test: "buyLotsOfFruit.buyLotsOfFruit([ ('apples', 1.25), ('pears',1.50), ('limes',1.75) ])"
diff --git a/tutorial/test_cases/q3/CONFIG b/tutorial/test_cases/q3/CONFIG
new file mode 100644
index 0000000..279f0f0
--- /dev/null
+++ b/tutorial/test_cases/q3/CONFIG
@@ -0,0 +1,2 @@
+max_points: "1"
+class: "PassAllTestsQuestion"
diff --git a/tutorial/test_cases/q3/select_shop1.solution b/tutorial/test_cases/q3/select_shop1.solution
new file mode 100644
index 0000000..083c232
--- /dev/null
+++ b/tutorial/test_cases/q3/select_shop1.solution
@@ -0,0 +1,3 @@
+# This is the solution file for test_cases/q3/select_shop1.test.
+# The result of evaluating the test must equal the below when cast to a string.
+result: ""
diff --git a/tutorial/test_cases/q3/select_shop1.test b/tutorial/test_cases/q3/select_shop1.test
new file mode 100644
index 0000000..05b358a
--- /dev/null
+++ b/tutorial/test_cases/q3/select_shop1.test
@@ -0,0 +1,21 @@
+class: "EvalTest"
+success: "shopSmart(order, shops) selects the cheapest shop"
+failure: "shopSmart(order, shops) must select the cheapest shop"
+
+# Python statements initializing variables for the test below.
+preamble: """
+import shop
+
+dir1 = {'apples': 2.0, 'oranges':1.0}
+shop1 =  shop.FruitShop('shop1',dir1)
+dir2 = {'apples': 1.0, 'oranges': 5.0}
+shop2 = shop.FruitShop('shop2',dir2)
+shops = [shop1, shop2]
+
+order = [('apples',1.0), ('oranges',3.0)]
+ans = shopSmart.shopSmart(order, shops)
+"""
+
+# A python expression to be evaluated.  This expression must return the 
+# same result for the student and instructor's code.
+test: "ans"
diff --git a/tutorial/test_cases/q3/select_shop2.solution b/tutorial/test_cases/q3/select_shop2.solution
new file mode 100644
index 0000000..8497881
--- /dev/null
+++ b/tutorial/test_cases/q3/select_shop2.solution
@@ -0,0 +1,3 @@
+# This is the solution file for test_cases/q3/select_shop2.test.
+# The result of evaluating the test must equal the below when cast to a string.
+result: ""
diff --git a/tutorial/test_cases/q3/select_shop2.test b/tutorial/test_cases/q3/select_shop2.test
new file mode 100644
index 0000000..04cb6f7
--- /dev/null
+++ b/tutorial/test_cases/q3/select_shop2.test
@@ -0,0 +1,21 @@
+class: "EvalTest"
+success: "shopSmart(order, shops) selects the cheapest shop"
+failure: "shopSmart(order, shops) must select the cheapest shop"
+
+# Python statements initializing variables for the test below.
+preamble: """
+import shop
+
+dir1 = {'apples': 2.0, 'oranges':1.0}
+shop1 =  shop.FruitShop('shop1',dir1)
+dir2 = {'apples': 1.0, 'oranges': 5.0}
+shop2 = shop.FruitShop('shop2',dir2)
+shops = [shop1, shop2]
+
+order = [('apples',3.0)]
+ans = shopSmart.shopSmart(order, shops)
+"""
+
+# A python expression to be evaluated.  This expression must return the 
+# same result for the student and instructor's code.
+test: "ans"
diff --git a/tutorial/test_cases/q3/select_shop3.solution b/tutorial/test_cases/q3/select_shop3.solution
new file mode 100644
index 0000000..a6b6352
--- /dev/null
+++ b/tutorial/test_cases/q3/select_shop3.solution
@@ -0,0 +1,3 @@
+# This is the solution file for test_cases/q3/select_shop3.test.
+# The result of evaluating the test must equal the below when cast to a string.
+result: ""
diff --git a/tutorial/test_cases/q3/select_shop3.test b/tutorial/test_cases/q3/select_shop3.test
new file mode 100644
index 0000000..24eeb06
--- /dev/null
+++ b/tutorial/test_cases/q3/select_shop3.test
@@ -0,0 +1,23 @@
+class: "EvalTest"
+success: "shopSmart(order, shops) selects the cheapest shop"
+failure: "shopSmart(order, shops) must select the cheapest shop"
+
+# Python statements initializing variables for the test below.
+preamble: """
+import shop
+
+dir1 = {'apples': 2.0, 'oranges':1.0}
+shop1 =  shop.FruitShop('shop1',dir1)
+dir2 = {'apples': 1.0, 'oranges': 5.0}
+shop2 = shop.FruitShop('shop2',dir2)
+dir3 = {'apples': 1.5, 'oranges': 2.0}
+shop3 = shop.FruitShop('shop3',dir3)
+shops = [shop1, shop2, shop3]
+
+order = [('apples',10.0), ('oranges',3.0)]
+ans = shopSmart.shopSmart(order, shops)
+"""
+
+# A python expression to be evaluated.  This expression must return the 
+# same result for the student and instructor's code.
+test: "ans"
diff --git a/tutorial/textDisplay.py b/tutorial/textDisplay.py
new file mode 100644
index 0000000..21f2b2c
--- /dev/null
+++ b/tutorial/textDisplay.py
@@ -0,0 +1,85 @@
+# textDisplay.py
+# --------------
+# Licensing Information:  You are free to use or extend these projects for
+# educational purposes provided that (1) you do not distribute or publish
+# solutions, (2) you retain this notice, and (3) you provide clear
+# attribution to UC Berkeley, including a link to http://ai.berkeley.edu.
+# 
+# Attribution Information: The Pacman AI projects were developed at UC Berkeley.
+# The core projects and autograders were primarily created by John DeNero
+# (denero@cs.berkeley.edu) and Dan Klein (klein@cs.berkeley.edu).
+# Student side autograding was added by Brad Miller, Nick Hay, and
+# Pieter Abbeel (pabbeel@cs.berkeley.edu).
+
+from __future__ import print_function
+import time
+
+try:
+    import pacman
+except:
+    pass
+
+DRAW_EVERY = 1
+SLEEP_TIME = 0  # This can be overwritten by __init__
+DISPLAY_MOVES = False
+QUIET = False  # Supresses output
+
+
+class NullGraphics:
+    def initialize(self, state, isBlue=False):
+        pass
+
+    def update(self, state):
+        pass
+
+    def checkNullDisplay(self):
+        return True
+
+    def pause(self):
+        time.sleep(SLEEP_TIME)
+
+    def draw(self, state):
+        print(state)
+
+    def updateDistributions(self, dist):
+        pass
+
+    def finish(self):
+        pass
+
+
+class PacmanGraphics:
+    def __init__(self, speed=None):
+        if speed != None:
+            global SLEEP_TIME
+            SLEEP_TIME = speed
+
+    def initialize(self, state, isBlue=False):
+        self.draw(state)
+        self.pause()
+        self.turn = 0
+        self.agentCounter = 0
+
+    def update(self, state):
+        numAgents = len(state.agentStates)
+        self.agentCounter = (self.agentCounter + 1) % numAgents
+        if self.agentCounter == 0:
+            self.turn += 1
+            if DISPLAY_MOVES:
+                ghosts = [pacman.nearestPoint(state.getGhostPosition(i)) for i in range(1, numAgents)]
+                print("%4d) P: %-8s" % (self.turn, str(pacman.nearestPoint(state.getPacmanPosition()))),
+                      '| Score: %-5d' % state.score, '| Ghosts:', ghosts)
+            if self.turn % DRAW_EVERY == 0:
+                self.draw(state)
+                self.pause()
+        if state._win or state._lose:
+            self.draw(state)
+
+    def pause(self):
+        time.sleep(SLEEP_TIME)
+
+    def draw(self, state):
+        print(state)
+
+    def finish(self):
+        pass
diff --git a/tutorial/town.py b/tutorial/town.py
new file mode 100644
index 0000000..dfbce01
--- /dev/null
+++ b/tutorial/town.py
@@ -0,0 +1,105 @@
+# town.py
+# -------
+# Licensing Information:  You are free to use or extend these projects for
+# educational purposes provided that (1) you do not distribute or publish
+# solutions, (2) you retain this notice, and (3) you provide clear
+# attribution to UC Berkeley, including a link to http://ai.berkeley.edu.
+# 
+# Attribution Information: The Pacman AI projects were developed at UC Berkeley.
+# The core projects and autograders were primarily created by John DeNero
+# (denero@cs.berkeley.edu) and Dan Klein (klein@cs.berkeley.edu).
+# Student side autograding was added by Brad Miller, Nick Hay, and
+# Pieter Abbeel (pabbeel@cs.berkeley.edu).
+
+
+import shop
+
+
+class Town:
+
+    def __init__(self, shops, distances):
+        """
+            shops: List of FruitShop objects
+
+            distances: Dictionary with keys as pairs (tuples) of names of places
+            ('home' or name strings of FruitShops) and numbers for values which
+            represent the distance between the two places in miles, e.g.
+            {('home','shop1') : 1, ('home','shop2') : 1, ('shop1','shop2') : 2}
+        """
+        self.shops = shops
+        self.distances = distances
+
+    def getFruitCostPerPoundOnRoute(self, fruit, route):
+        """
+            fruit: Fruit string
+
+            route: List of shop names
+        Returns the best cost per pound of 'fruit' at any of the shops along 
+        the route. If none of the shops carry 'fruit', returns None
+        """
+        routeShops = [shop for shop in self.shops if shop.getName() in route]
+        costs = []
+        for shop in routeShops:
+            cost = shop.getCostPerPound(fruit)
+            if cost is not None:
+                costs.append(cost)
+        if not costs:
+            # None of the shops carry this fruit
+            return None
+        return min(costs)
+
+    def allFruitsCarriedAtShops(self, orderList, shops):
+        """
+            orderList: List of (fruit, numPounds) tuples
+
+            shops: List of shop names
+        Returns whether all fruit in the order list can be purchased at at least
+        one of these shops.
+        """
+        return None not in [self.getFruitCostPerPoundOnRoute(fruit, shops)
+                            for fruit, _ in orderList]
+
+    def getDistance(self, loc1, loc2):
+        """
+            loc1: A name of a place ('home' or the name of a FruitShop in town)
+
+            loc2: A name of a place ('home' or the name of a FruitShop in town)
+        Returns the distance between these two places in this town.
+        """
+        if (loc1, loc2) in self.distances:
+            return self.distances[(loc1, loc2)]
+        return self.distances[(loc2, loc1)]
+
+    def getTotalDistanceOnRoute(self, route):
+        """
+            route: List of shop names
+        Returns the total distance traveled by starting at 'home', going to 
+        each shop on the route in order, then returning to 'home'
+        """
+        if not route:
+            return 0
+        totalDistance = self.getDistance('home', route[0])
+        for i in xrange(len(route) - 1):
+            totalDistance += self.getDistance(route[i], route[i + 1])
+        totalDistance += self.getDistance(route[-1], 'home')
+        return totalDistance
+
+    def getPriceOfOrderOnRoute(self, orderList, route, gasCost):
+        """
+            orderList: List of (fruit, numPounds) tuples
+
+            route: List of shop names
+
+            gasCost: A number representing the cost of driving 1 mile
+        Returns cost of orderList on this route. If any fruit are not available
+        on this route, returns None. 
+        """
+        totalCost = self.getTotalDistanceOnRoute(route) * gasCost
+        for fruit, numPounds in orderList:
+            costPerPound = self.getFruitCostPerPoundOnRoute(fruit, route)
+            if costPerPound is not None:
+                totalCost += numPounds * costPerPound
+        return totalCost
+
+    def getShops(self):
+        return self.shops
diff --git a/tutorial/tutorialTestClasses.py b/tutorial/tutorialTestClasses.py
new file mode 100644
index 0000000..07ea4c3
--- /dev/null
+++ b/tutorial/tutorialTestClasses.py
@@ -0,0 +1,57 @@
+# tutorialTestClasses.py
+# ----------------------
+# Licensing Information:  You are free to use or extend these projects for
+# educational purposes provided that (1) you do not distribute or publish
+# solutions, (2) you retain this notice, and (3) you provide clear
+# attribution to UC Berkeley, including a link to http://ai.berkeley.edu.
+# 
+# Attribution Information: The Pacman AI projects were developed at UC Berkeley.
+# The core projects and autograders were primarily created by John DeNero
+# (denero@cs.berkeley.edu) and Dan Klein (klein@cs.berkeley.edu).
+# Student side autograding was added by Brad Miller, Nick Hay, and
+# Pieter Abbeel (pabbeel@cs.berkeley.edu).
+
+
+import testClasses
+
+
+# Simple test case which evals an arbitrary piece of python code.
+# The test is correct if the output of the code given the student's
+# solution matches that of the instructor's.
+class EvalTest(testClasses.TestCase):
+
+    def __init__(self, question, testDict):
+        super(EvalTest, self).__init__(question, testDict)
+        self.preamble = compile(testDict.get('preamble', ""), "%s.preamble" % self.getPath(), 'exec')
+        self.test = compile(testDict['test'], "%s.test" % self.getPath(), 'eval')
+        self.success = testDict['success']
+        self.failure = testDict['failure']
+
+    def evalCode(self, moduleDict):
+        bindings = dict(moduleDict)
+        # exec self.preamble in bindings
+        exec(self.preamble, bindings)
+        return str(eval(self.test, bindings))
+
+    def execute(self, grades, moduleDict, solutionDict):
+        result = self.evalCode(moduleDict)
+        if result == solutionDict['result']:
+            grades.addMessage('PASS: %s' % self.path)
+            grades.addMessage('\t%s' % self.success)
+            return True
+        else:
+            grades.addMessage('FAIL: %s' % self.path)
+            grades.addMessage('\t%s' % self.failure)
+            grades.addMessage('\tstudent result: "%s"' % result)
+            grades.addMessage('\tcorrect result: "%s"' % solutionDict['result'])
+
+        return False
+
+    def writeSolution(self, moduleDict, filePath):
+        handle = open(filePath, 'w')
+        handle.write('# This is the solution file for %s.\n' % self.path)
+        handle.write('# The result of evaluating the test must equal the below when cast to a string.\n')
+
+        handle.write('result: "%s"\n' % self.evalCode(moduleDict))
+        handle.close()
+        return True
diff --git a/tutorial/util.py b/tutorial/util.py
new file mode 100644
index 0000000..50cd74a
--- /dev/null
+++ b/tutorial/util.py
@@ -0,0 +1,696 @@
+# util.py
+# -------
+# Licensing Information:  You are free to use or extend these projects for
+# educational purposes provided that (1) you do not distribute or publish
+# solutions, (2) you retain this notice, and (3) you provide clear
+# attribution to UC Berkeley, including a link to http://ai.berkeley.edu.
+# 
+# Attribution Information: The Pacman AI projects were developed at UC Berkeley.
+# The core projects and autograders were primarily created by John DeNero
+# (denero@cs.berkeley.edu) and Dan Klein (klein@cs.berkeley.edu).
+# Student side autograding was added by Brad Miller, Nick Hay, and
+# Pieter Abbeel (pabbeel@cs.berkeley.edu).
+
+
+# util.py
+# -------
+# Licensing Information:  You are free to use or extend these projects for
+# educational purposes provided that (1) you do not distribute or publish
+# solutions, (2) you retain this notice, and (3) you provide clear
+# attribution to UC Berkeley, including a link to http://ai.berkeley.edu.
+# 
+# Attribution Information: The Pacman AI projects were developed at UC Berkeley.
+# The core projects and autograders were primarily created by John DeNero
+# (denero@cs.berkeley.edu) and Dan Klein (klein@cs.berkeley.edu).
+# Student side autograding was added by Brad Miller, Nick Hay, and
+# Pieter Abbeel (pabbeel@cs.berkeley.edu).
+
+
+import sys
+import inspect
+import heapq, random
+
+
+# import cStringIO
+
+
+class FixedRandom:
+    def __init__(self):
+        fixedState = (3, (2147483648, 507801126, 683453281, 310439348, 2597246090,
+                          2209084787, 2267831527, 979920060, 3098657677, 37650879, 807947081, 3974896263,
+                          881243242, 3100634921, 1334775171, 3965168385, 746264660, 4074750168, 500078808,
+                          776561771, 702988163, 1636311725, 2559226045, 157578202, 2498342920, 2794591496,
+                          4130598723, 496985844, 2944563015, 3731321600, 3514814613, 3362575829, 3038768745,
+                          2206497038, 1108748846, 1317460727, 3134077628, 988312410, 1674063516, 746456451,
+                          3958482413, 1857117812, 708750586, 1583423339, 3466495450, 1536929345, 1137240525,
+                          3875025632, 2466137587, 1235845595, 4214575620, 3792516855, 657994358, 1241843248,
+                          1695651859, 3678946666, 1929922113, 2351044952, 2317810202, 2039319015, 460787996, 3654096216,
+                          4068721415, 1814163703, 2904112444, 1386111013, 574629867, 2654529343, 3833135042, 2725328455,
+                          552431551, 4006991378, 1331562057, 3710134542, 303171486, 1203231078, 2670768975, 54570816,
+                          2679609001, 578983064, 1271454725, 3230871056, 2496832891, 2944938195, 1608828728, 367886575,
+                          2544708204, 103775539, 1912402393, 1098482180, 2738577070, 3091646463, 1505274463, 2079416566,
+                          659100352, 839995305, 1696257633, 274389836, 3973303017, 671127655, 1061109122, 517486945,
+                          1379749962, 3421383928, 3116950429, 2165882425, 2346928266, 2892678711, 2936066049,
+                          1316407868, 2873411858, 4279682888, 2744351923, 3290373816, 1014377279, 955200944, 4220990860,
+                          2386098930, 1772997650, 3757346974, 1621616438, 2877097197, 442116595, 2010480266, 2867861469,
+                          2955352695, 605335967, 2222936009, 2067554933, 4129906358, 1519608541, 1195006590, 1942991038,
+                          2736562236, 279162408, 1415982909, 4099901426, 1732201505, 2934657937, 860563237, 2479235483,
+                          3081651097, 2244720867, 3112631622, 1636991639, 3860393305, 2312061927, 48780114, 1149090394,
+                          2643246550, 1764050647, 3836789087, 3474859076, 4237194338, 1735191073, 2150369208, 92164394,
+                          756974036, 2314453957, 323969533, 4267621035, 283649842, 810004843, 727855536, 1757827251,
+                          3334960421, 3261035106, 38417393, 2660980472, 1256633965, 2184045390, 811213141, 2857482069,
+                          2237770878, 3891003138, 2787806886, 2435192790, 2249324662, 3507764896, 995388363, 856944153,
+                          619213904, 3233967826, 3703465555, 3286531781, 3863193356, 2992340714, 413696855, 3865185632,
+                          1704163171, 3043634452, 2225424707, 2199018022, 3506117517, 3311559776, 3374443561,
+                          1207829628, 668793165, 1822020716, 2082656160, 1160606415, 3034757648, 741703672, 3094328738,
+                          459332691, 2702383376, 1610239915, 4162939394, 557861574, 3805706338, 3832520705, 1248934879,
+                          3250424034, 892335058, 74323433, 3209751608, 3213220797, 3444035873, 3743886725, 1783837251,
+                          610968664, 580745246, 4041979504, 201684874, 2673219253, 1377283008, 3497299167, 2344209394,
+                          2304982920, 3081403782, 2599256854, 3184475235, 3373055826, 695186388, 2423332338, 222864327,
+                          1258227992, 3627871647, 3487724980, 4027953808, 3053320360, 533627073, 3026232514, 2340271949,
+                          867277230, 868513116, 2158535651, 2487822909, 3428235761, 3067196046, 3435119657, 1908441839,
+                          788668797, 3367703138, 3317763187, 908264443, 2252100381, 764223334, 4127108988, 384641349,
+                          3377374722, 1263833251, 1958694944, 3847832657, 1253909612, 1096494446, 555725445, 2277045895,
+                          3340096504, 1383318686, 4234428127, 1072582179, 94169494, 1064509968, 2681151917, 2681864920,
+                          734708852, 1338914021, 1270409500, 1789469116, 4191988204, 1716329784, 2213764829, 3712538840,
+                          919910444, 1318414447, 3383806712, 3054941722, 3378649942, 1205735655, 1268136494, 2214009444,
+                          2532395133, 3232230447, 230294038, 342599089, 772808141, 4096882234, 3146662953, 2784264306,
+                          1860954704, 2675279609, 2984212876, 2466966981, 2627986059, 2985545332, 2578042598,
+                          1458940786, 2944243755, 3959506256, 1509151382, 325761900, 942251521, 4184289782, 2756231555,
+                          3297811774, 1169708099, 3280524138, 3805245319, 3227360276, 3199632491, 2235795585,
+                          2865407118, 36763651, 2441503575, 3314890374, 1755526087, 17915536, 1196948233, 949343045,
+                          3815841867, 489007833, 2654997597, 2834744136, 417688687, 2843220846, 85621843, 747339336,
+                          2043645709, 3520444394, 1825470818, 647778910, 275904777, 1249389189, 3640887431, 4200779599,
+                          323384601, 3446088641, 4049835786, 1718989062, 3563787136, 44099190, 3281263107, 22910812,
+                          1826109246, 745118154, 3392171319, 1571490704, 354891067, 815955642, 1453450421, 940015623,
+                          796817754, 1260148619, 3898237757, 176670141, 1870249326, 3317738680, 448918002, 4059166594,
+                          2003827551, 987091377, 224855998, 3520570137, 789522610, 2604445123, 454472869, 475688926,
+                          2990723466, 523362238, 3897608102, 806637149, 2642229586, 2928614432, 1564415411, 1691381054,
+                          3816907227, 4082581003, 1895544448, 3728217394, 3214813157, 4054301607, 1882632454,
+                          2873728645, 3694943071, 1297991732, 2101682438, 3952579552, 678650400, 1391722293, 478833748,
+                          2976468591, 158586606, 2576499787, 662690848, 3799889765, 3328894692, 2474578497, 2383901391,
+                          1718193504, 3003184595, 3630561213, 1929441113, 3848238627, 1594310094, 3040359840,
+                          3051803867, 2462788790, 954409915, 802581771, 681703307, 545982392, 2738993819, 8025358,
+                          2827719383, 770471093, 3484895980, 3111306320, 3900000891, 2116916652, 397746721, 2087689510,
+                          721433935, 1396088885, 2751612384, 1998988613, 2135074843, 2521131298, 707009172, 2398321482,
+                          688041159, 2264560137, 482388305, 207864885, 3735036991, 3490348331, 1963642811, 3260224305,
+                          3493564223, 1939428454, 1128799656, 1366012432, 2858822447, 1428147157, 2261125391,
+                          1611208390, 1134826333, 2374102525, 3833625209, 2266397263, 3189115077, 770080230, 2674657172,
+                          4280146640, 3604531615, 4235071805, 3436987249, 509704467, 2582695198, 4256268040, 3391197562,
+                          1460642842, 1617931012, 457825497, 1031452907, 1330422862, 4125947620, 2280712485, 431892090,
+                          2387410588, 2061126784, 896457479, 3480499461, 2488196663, 4021103792, 1877063114, 2744470201,
+                          1046140599, 2129952955, 3583049218, 4217723693, 2720341743, 820661843, 1079873609, 3360954200,
+                          3652304997, 3335838575, 2178810636, 1908053374, 4026721976, 1793145418, 476541615, 973420250,
+                          515553040, 919292001, 2601786155, 1685119450, 3030170809, 1590676150, 1665099167, 651151584,
+                          2077190587, 957892642, 646336572, 2743719258, 866169074, 851118829, 4225766285, 963748226,
+                          799549420, 1955032629, 799460000, 2425744063, 2441291571, 1928963772, 528930629, 2591962884,
+                          3495142819, 1896021824, 901320159, 3181820243, 843061941, 3338628510, 3782438992, 9515330,
+                          1705797226, 953535929, 764833876, 3202464965, 2970244591, 519154982, 3390617541, 566616744,
+                          3438031503, 1853838297, 170608755, 1393728434, 676900116, 3184965776, 1843100290, 78995357,
+                          2227939888, 3460264600, 1745705055, 1474086965, 572796246, 4081303004, 882828851, 1295445825,
+                          137639900, 3304579600, 2722437017, 4093422709, 273203373, 2666507854, 3998836510, 493829981,
+                          1623949669, 3482036755, 3390023939, 833233937, 1639668730, 1499455075, 249728260, 1210694006,
+                          3836497489, 1551488720, 3253074267, 3388238003, 2372035079, 3945715164, 2029501215,
+                          3362012634, 2007375355, 4074709820, 631485888, 3135015769, 4273087084, 3648076204, 2739943601,
+                          1374020358, 1760722448, 3773939706, 1313027823, 1895251226, 4224465911, 421382535, 1141067370,
+                          3660034846, 3393185650, 1850995280, 1451917312, 3841455409, 3926840308, 1397397252,
+                          2572864479, 2500171350, 3119920613, 531400869, 1626487579, 1099320497, 407414753, 2438623324,
+                          99073255, 3175491512, 656431560, 1153671785, 236307875, 2824738046, 2320621382, 892174056,
+                          230984053, 719791226, 2718891946, 624), None)
+        self.random = random.Random()
+        self.random.setstate(fixedState)
+
+
+"""
+ Data structures useful for implementing SearchAgents
+"""
+
+
+class Stack:
+    "A container with a last-in-first-out (LIFO) queuing policy."
+
+    def __init__(self):
+        self.list = []
+
+    def push(self, item):
+        "Push 'item' onto the stack"
+        self.list.append(item)
+
+    def pop(self):
+        "Pop the most recently pushed item from the stack"
+        return self.list.pop()
+
+    def isEmpty(self):
+        "Returns true if the stack is empty"
+        return len(self.list) == 0
+
+
+class Queue:
+    "A container with a first-in-first-out (FIFO) queuing policy."
+
+    def __init__(self):
+        self.list = []
+
+    def push(self, item):
+        "Enqueue the 'item' into the queue"
+        self.list.insert(0, item)
+
+    def pop(self):
+        """
+          Dequeue the earliest enqueued item still in the queue. This
+          operation removes the item from the queue.
+        """
+        return self.list.pop()
+
+    def isEmpty(self):
+        "Returns true if the queue is empty"
+        return len(self.list) == 0
+
+
+class PriorityQueue:
+    """
+      Implements a priority queue data structure. Each inserted item
+      has a priority associated with it and the client is usually interested
+      in quick retrieval of the lowest-priority item in the queue. This
+      data structure allows O(1) access to the lowest-priority item.
+    """
+
+    def __init__(self):
+        self.heap = []
+        self.count = 0
+
+    def push(self, item, priority):
+        entry = (priority, self.count, item)
+        heapq.heappush(self.heap, entry)
+        self.count += 1
+
+    def pop(self):
+        (_, _, item) = heapq.heappop(self.heap)
+        return item
+
+    def isEmpty(self):
+        return len(self.heap) == 0
+
+    def update(self, item, priority):
+        # If item already in priority queue with higher priority, update its priority and rebuild the heap.
+        # If item already in priority queue with equal or lower priority, do nothing.
+        # If item not in priority queue, do the same thing as self.push.
+        for index, (p, c, i) in enumerate(self.heap):
+            if i == item:
+                if p <= priority:
+                    break
+                del self.heap[index]
+                self.heap.append((priority, c, item))
+                heapq.heapify(self.heap)
+                break
+        else:
+            self.push(item, priority)
+
+
+class PriorityQueueWithFunction(PriorityQueue):
+    """
+    Implements a priority queue with the same push/pop signature of the
+    Queue and the Stack classes. This is designed for drop-in replacement for
+    those two classes. The caller has to provide a priority function, which
+    extracts each item's priority.
+    """
+
+    def __init__(self, priorityFunction):
+        "priorityFunction (item) -> priority"
+        self.priorityFunction = priorityFunction  # store the priority function
+        PriorityQueue.__init__(self)  # super-class initializer
+
+    def push(self, item):
+        "Adds an item to the queue with priority from the priority function"
+        PriorityQueue.push(self, item, self.priorityFunction(item))
+
+
+def manhattanDistance(xy1, xy2):
+    "Returns the Manhattan distance between points xy1 and xy2"
+    return abs(xy1[0] - xy2[0]) + abs(xy1[1] - xy2[1])
+
+
+"""
+  Data structures and functions useful for various course projects
+
+  The search project should not need anything below this line.
+"""
+
+
+class Counter(dict):
+    """
+    A counter keeps track of counts for a set of keys.
+
+    The counter class is an extension of the standard python
+    dictionary type.  It is specialized to have number values
+    (integers or floats), and includes a handful of additional
+    functions to ease the task of counting data.  In particular,
+    all keys are defaulted to have value 0.  Using a dictionary:
+
+    a = {}
+    print(a['test'])
+
+    would give an error, while the Counter class analogue:
+
+    >>> a = Counter()
+    >>> print(a['test'])
+    0
+
+    returns the default 0 value. Note that to reference a key
+    that you know is contained in the counter,
+    you can still use the dictionary syntax:
+
+    >>> a = Counter()
+    >>> a['test'] = 2
+    >>> print(a['test'])
+    2
+
+    This is very useful for counting things without initializing their counts,
+    see for example:
+
+    >>> a['blah'] += 1
+    >>> print(a['blah'])
+    1
+
+    The counter also includes additional functionality useful in implementing
+    the classifiers for this assignment.  Two counters can be added,
+    subtracted or multiplied together.  See below for details.  They can
+    also be normalized and their total count and arg max can be extracted.
+    """
+
+    def __getitem__(self, idx):
+        self.setdefault(idx, 0)
+        return dict.__getitem__(self, idx)
+
+    def incrementAll(self, keys, count):
+        """
+        Increments all elements of keys by the same count.
+
+        >>> a = Counter()
+        >>> a.incrementAll(['one','two', 'three'], 1)
+        >>> a['one']
+        1
+        >>> a['two']
+        1
+        """
+        for key in keys:
+            self[key] += count
+
+    def argMax(self):
+        """
+        Returns the key with the highest value.
+        """
+        if len(self.keys()) == 0: return None
+        all = self.items()
+        values = [x[1] for x in all]
+        maxIndex = values.index(max(values))
+        return all[maxIndex][0]
+
+    def sortedKeys(self):
+        """
+        Returns a list of keys sorted by their values.  Keys
+        with the highest values will appear first.
+
+        >>> a = Counter()
+        >>> a['first'] = -2
+        >>> a['second'] = 4
+        >>> a['third'] = 1
+        >>> a.sortedKeys()
+        ['second', 'third', 'first']
+        """
+        sortedItems = self.items()
+        compare = lambda x, y: sign(y[1] - x[1])
+        sortedItems.sort(cmp=compare)
+        return [x[0] for x in sortedItems]
+
+    def totalCount(self):
+        """
+        Returns the sum of counts for all keys.
+        """
+        return sum(self.values())
+
+    def normalize(self):
+        """
+        Edits the counter such that the total count of all
+        keys sums to 1.  The ratio of counts for all keys
+        will remain the same. Note that normalizing an empty
+        Counter will result in an error.
+        """
+        total = float(self.totalCount())
+        if total == 0: return
+        for key in self.keys():
+            self[key] = self[key] / total
+
+    def divideAll(self, divisor):
+        """
+        Divides all counts by divisor
+        """
+        divisor = float(divisor)
+        for key in self:
+            self[key] /= divisor
+
+    def copy(self):
+        """
+        Returns a copy of the counter
+        """
+        return Counter(dict.copy(self))
+
+    def __mul__(self, y):
+        """
+        Multiplying two counters gives the dot product of their vectors where
+        each unique label is a vector element.
+
+        >>> a = Counter()
+        >>> b = Counter()
+        >>> a['first'] = -2
+        >>> a['second'] = 4
+        >>> b['first'] = 3
+        >>> b['second'] = 5
+        >>> a['third'] = 1.5
+        >>> a['fourth'] = 2.5
+        >>> a * b
+        14
+        """
+        sum = 0
+        x = self
+        if len(x) > len(y):
+            x, y = y, x
+        for key in x:
+            if key not in y:
+                continue
+            sum += x[key] * y[key]
+        return sum
+
+    def __radd__(self, y):
+        """
+        Adding another counter to a counter increments the current counter
+        by the values stored in the second counter.
+
+        >>> a = Counter()
+        >>> b = Counter()
+        >>> a['first'] = -2
+        >>> a['second'] = 4
+        >>> b['first'] = 3
+        >>> b['third'] = 1
+        >>> a += b
+        >>> a['first']
+        1
+        """
+        for key, value in y.items():
+            self[key] += value
+
+    def __add__(self, y):
+        """
+        Adding two counters gives a counter with the union of all keys and
+        counts of the second added to counts of the first.
+
+        >>> a = Counter()
+        >>> b = Counter()
+        >>> a['first'] = -2
+        >>> a['second'] = 4
+        >>> b['first'] = 3
+        >>> b['third'] = 1
+        >>> (a + b)['first']
+        1
+        """
+        addend = Counter()
+        for key in self:
+            if key in y:
+                addend[key] = self[key] + y[key]
+            else:
+                addend[key] = self[key]
+        for key in y:
+            if key in self:
+                continue
+            addend[key] = y[key]
+        return addend
+
+    def __sub__(self, y):
+        """
+        Subtracting a counter from another gives a counter with the union of all keys and
+        counts of the second subtracted from counts of the first.
+
+        >>> a = Counter()
+        >>> b = Counter()
+        >>> a['first'] = -2
+        >>> a['second'] = 4
+        >>> b['first'] = 3
+        >>> b['third'] = 1
+        >>> (a - b)['first']
+        -5
+        """
+        addend = Counter()
+        for key in self:
+            if key in y:
+                addend[key] = self[key] - y[key]
+            else:
+                addend[key] = self[key]
+        for key in y:
+            if key in self:
+                continue
+            addend[key] = -1 * y[key]
+        return addend
+
+
+def raiseNotDefined():
+    fileName = inspect.stack()[1][1]
+    line = inspect.stack()[1][2]
+    method = inspect.stack()[1][3]
+
+    print("*** Method not implemented: %s at line %s of %s" % (method, line, fileName))
+    sys.exit(1)
+
+
+def normalize(vectorOrCounter):
+    """
+    normalize a vector or counter by dividing each value by the sum of all values
+    """
+    normalizedCounter = Counter()
+    if type(vectorOrCounter) == type(normalizedCounter):
+        counter = vectorOrCounter
+        total = float(counter.totalCount())
+        if total == 0: return counter
+        for key in counter.keys():
+            value = counter[key]
+            normalizedCounter[key] = value / total
+        return normalizedCounter
+    else:
+        vector = vectorOrCounter
+        s = float(sum(vector))
+        if s == 0: return vector
+        return [el / s for el in vector]
+
+
+def nSample(distribution, values, n):
+    if sum(distribution) != 1:
+        distribution = normalize(distribution)
+    rand = [random.random() for i in range(n)]
+    rand.sort()
+    samples = []
+    samplePos, distPos, cdf = 0, 0, distribution[0]
+    while samplePos < n:
+        if rand[samplePos] < cdf:
+            samplePos += 1
+            samples.append(values[distPos])
+        else:
+            distPos += 1
+            cdf += distribution[distPos]
+    return samples
+
+
+def sample(distribution, values=None):
+    if type(distribution) == Counter:
+        items = sorted(distribution.items())
+        distribution = [i[1] for i in items]
+        values = [i[0] for i in items]
+    if sum(distribution) != 1:
+        distribution = normalize(distribution)
+    choice = random.random()
+    i, total = 0, distribution[0]
+    while choice > total:
+        i += 1
+        total += distribution[i]
+    return values[i]
+
+
+def sampleFromCounter(ctr):
+    items = sorted(ctr.items())
+    return sample([v for k, v in items], [k for k, v in items])
+
+
+def getProbability(value, distribution, values):
+    """
+      Gives the probability of a value under a discrete distribution
+      defined by (distributions, values).
+    """
+    total = 0.0
+    for prob, val in zip(distribution, values):
+        if val == value:
+            total += prob
+    return total
+
+
+def flipCoin(p):
+    r = random.random()
+    return r < p
+
+
+def chooseFromDistribution(distribution):
+    "Takes either a counter or a list of (prob, key) pairs and samples"
+    if type(distribution) == dict or type(distribution) == Counter:
+        return sample(distribution)
+    r = random.random()
+    base = 0.0
+    for prob, element in distribution:
+        base += prob
+        if r <= base: return element
+
+
+def nearestPoint(pos):
+    """
+    Finds the nearest grid point to a position (discretizes).
+    """
+    (current_row, current_col) = pos
+
+    grid_row = int(current_row + 0.5)
+    grid_col = int(current_col + 0.5)
+    return (grid_row, grid_col)
+
+
+def sign(x):
+    """
+    Returns 1 or -1 depending on the sign of x
+    """
+    if (x >= 0):
+        return 1
+    else:
+        return -1
+
+
+def arrayInvert(array):
+    """
+    Inverts a matrix stored as a list of lists.
+    """
+    result = [[] for i in array]
+    for outer in array:
+        for inner in range(len(outer)):
+            result[inner].append(outer[inner])
+    return result
+
+
+def matrixAsList(matrix, value=True):
+    """
+    Turns a matrix into a list of coordinates matching the specified value
+    """
+    rows, cols = len(matrix), len(matrix[0])
+    cells = []
+    for row in range(rows):
+        for col in range(cols):
+            if matrix[row][col] == value:
+                cells.append((row, col))
+    return cells
+
+
+def lookup(name, namespace):
+    """
+    Get a method or class from any imported module from its name.
+    Usage: lookup(functionName, globals())
+    """
+    dots = name.count('.')
+    if dots > 0:
+        moduleName, objName = '.'.join(name.split('.')[:-1]), name.split('.')[-1]
+        module = __import__(moduleName)
+        return getattr(module, objName)
+    else:
+        modules = [obj for obj in namespace.values() if str(type(obj)) == ""]
+        options = [getattr(module, name) for module in modules if name in dir(module)]
+        options += [obj[1] for obj in namespace.items() if obj[0] == name]
+        if len(options) == 1: return options[0]
+        if len(options) > 1: raise Exception('Name conflict for %s')
+        raise Exception('%s not found as a method or class' % name)
+
+
+def pause():
+    """
+    Pauses the output stream awaiting user feedback.
+    """
+    print("")
+    raw_input()
+
+
+# code to handle timeouts
+#
+# FIXME
+# NOTE: TimeoutFuncton is NOT reentrant.  Later timeouts will silently
+# disable earlier timeouts.  Could be solved by maintaining a global list
+# of active time outs.  Currently, questions which have test cases calling
+# this have all student code so wrapped.
+#
+import signal
+import time
+
+
+class TimeoutFunctionException(Exception):
+    """Exception to raise on a timeout"""
+    pass
+
+
+class TimeoutFunction:
+    def __init__(self, function, timeout):
+        self.timeout = timeout
+        self.function = function
+
+    def handle_timeout(self, signum, frame):
+        raise TimeoutFunctionException()
+
+    def __call__(self, *args, **keyArgs):
+        # If we have SIGALRM signal, use it to cause an exception if and
+        # when this function runs too long.  Otherwise check the time taken
+        # after the method has returned, and throw an exception then.
+        if hasattr(signal, 'SIGALRM'):
+            old = signal.signal(signal.SIGALRM, self.handle_timeout)
+            signal.alarm(self.timeout)
+            try:
+                result = self.function(*args, **keyArgs)
+            finally:
+                signal.signal(signal.SIGALRM, old)
+            signal.alarm(0)
+        else:
+            startTime = time.time()
+            result = self.function(*args, **keyArgs)
+            timeElapsed = time.time() - startTime
+            if timeElapsed >= self.timeout:
+                self.handle_timeout(None, None)
+        return result
+
+
+_ORIGINAL_STDOUT = None
+_ORIGINAL_STDERR = None
+_MUTED = False
+
+
+class WritableNull:
+    def write(self, string):
+        pass
+
+
+def mutePrint():
+    global _ORIGINAL_STDOUT, _ORIGINAL_STDERR, _MUTED
+    if _MUTED:
+        return
+    _MUTED = True
+
+    _ORIGINAL_STDOUT = sys.stdout
+    # _ORIGINAL_STDERR = sys.stderr
+    sys.stdout = WritableNull()
+    # sys.stderr = WritableNull()
+
+
+def unmutePrint():
+    global _ORIGINAL_STDOUT, _ORIGINAL_STDERR, _MUTED
+    if not _MUTED:
+        return
+    _MUTED = False
+
+    sys.stdout = _ORIGINAL_STDOUT
+    # sys.stderr = _ORIGINAL_STDERR