diff --git a/Code/Python_Code/15.1.1_Sweep/Sweep.py b/Code/Python_Code/15.1.1_Sweep/Sweep.py
index 28c6e08..89f941a 100644
--- a/Code/Python_Code/15.1.1_Sweep/Sweep.py
+++ b/Code/Python_Code/15.1.1_Sweep/Sweep.py
@@ -33,11 +33,11 @@ def servoWrite(angle):      # make the servo rotate to specific angle (0-180 deg
     
 def loop():
     while True:
-        for dc in range(0, 181, 1):   #make servo rotate from 0° to 180°
+        for dc in range(0, 181, 1):   #make servo rotate from 0 to 180 deg
             servoWrite(dc)     # Write to servo
             time.sleep(0.001)
         time.sleep(0.5)
-        for dc in range(180, -1, -1): #make servo rotate from 180°to 0°
+        for dc in range(180, -1, -1): #make servo rotate from 180 to 0 deg
             servoWrite(dc)
             time.sleep(0.001)
         time.sleep(0.5)
diff --git a/Code/Python_Code/16.1.1_SteppingMotor/SteppingMotor.py b/Code/Python_Code/16.1.1_SteppingMotor/SteppingMotor.py
index dcbf669..67992df 100644
--- a/Code/Python_Code/16.1.1_SteppingMotor/SteppingMotor.py
+++ b/Code/Python_Code/16.1.1_SteppingMotor/SteppingMotor.py
@@ -22,7 +22,7 @@ def moveOnePeriod(direction,ms):
     for j in range(0,4,1):      #cycle for power supply order
         for i in range(0,4,1):  #assign to each pin, a total of 4 pins
             if (direction == 1):#power supply order clockwise
-                GPIO.output(motorPins[i],((CCWStep[j] == 1<<i) and GPIO.HIGH orGPIO.LOW))
+                GPIO.output(motorPins[i],((CCWStep[j] == 1<<i) and GPIO.HIGH or GPIO.LOW))
             else :              #power supply order anticlockwise
                 GPIO.output(motorPins[i],((CWStep[j] == 1<<i) and GPIO.HIGH or GPIO.LOW))
         if(ms<3):       #the delay can not be less than 3ms, otherwise it will exceed speed limit of the motor
@@ -39,9 +39,9 @@ def motorStop():
             
 def loop():
     while True:
-        moveSteps(1,3,512)  #rotating   360° clockwise, a total of 2048 steps in a circle, namely, 512 cycles.
+        moveSteps(1,3,512)  #rotating   360 deg clockwise, a total of 2048 steps in a circle, namely, 512 cycles.
         time.sleep(0.5)
-        moveSteps(0,3,512)  #rotating 360° anticlockwise
+        moveSteps(0,3,512)  #rotating 360 deg anticlockwise
         time.sleep(0.5)
 
 def destroy():
diff --git a/Code/Python_Code/22.1.1_MatrixKeypad/Keypad.py b/Code/Python_Code/22.1.1_MatrixKeypad/Keypad.py
index 0f6bd5d..202be7a 100644
--- a/Code/Python_Code/22.1.1_MatrixKeypad/Keypad.py
+++ b/Code/Python_Code/22.1.1_MatrixKeypad/Keypad.py
@@ -6,7 +6,7 @@
 ########################################################################
 import RPi.GPIO as GPIO 
 import time
-#class Key：Define some of the properties of Key
+#class Key:Define some of the properties of Key
 class Key(object):
 	NO_KEY = '\0'
 	#Defines the four states of Key
diff --git a/Code/Python_Code/22.1.1_MatrixKeypad/MatrixKeypad.py b/Code/Python_Code/22.1.1_MatrixKeypad/MatrixKeypad.py
index 1f3cb48..66dc61d 100644
--- a/Code/Python_Code/22.1.1_MatrixKeypad/MatrixKeypad.py
+++ b/Code/Python_Code/22.1.1_MatrixKeypad/MatrixKeypad.py
@@ -26,4 +26,5 @@ if __name__ == '__main__':     #Program start from here
     print "Program is starting ... "
     try:
         loop()
-    except KeyboardInterrupt:  #When 'Ctrl+C' is pressed, exit the program.      GPIO.cleanup()  
+    except KeyboardInterrupt:  #When 'Ctrl+C' is pressed, exit the program.      
+		GPIO.cleanup()