Programming Exercise 3-7
# Global variables
RED = “red”
BLUE = “blue”
YELLOW = “yellow”
# Get first color from the user.
color1 = input(‘Enter the first primary color in lower case letters: ‘)
# Get second color from the user.
color2 = input(‘Enter the second primary color in lower case letters: ‘)
# Check validity of first color.
if color1 != RED and color1 != BLUE and color1 != YELLOW:
print(‘Error: The first color you entered is invalid.’)
# Check validity of second color.
elif color2 != RED and color2 != BLUE and color2 != YELLOW:
print(‘Error: The second color you entered is invalid.’)
# Check if the two colors are the same.
elif color1 == color2:
print(‘Error: The two colors you entered are the same.’)
# Display the secondary color resulting from mixing the two colors.
else:
# Determine secondary color if the first color is red.
if color1 == RED:
if color2 == BLUE:
print(‘purple’)
else: # Color 2 must be yellow
print(‘orange’)
# Determine secondary color if first color is blue.
elif color1 == BLUE:
if color2 == RED:
print(‘purple’)
else: # Color 2 must be yellow.
print(‘green’)
else: # First color must be yellow.
if color2 == RED:
print(‘orange’)
else: # Color 2 must be blue.
print(‘green’)