Question

OBJECTIVES:

1. To understand repetition structures
2. To use while loops in a program
3. To understand break and/or continue instructions

1. Write a Python program (with comments) to do the following:
   1. Create a variable count and initialize it to 0
   2. Create a variable colors and initialize it to [] (i.e. an empty list)
   3. Ask the user if they would like to enter up to 3 favorite colors. They should enter ‘y’ or ‘n’. Assume they will enter a valid input. Save the response to a variable flag.
   4. while flag is not ‘n’ and count is less than 3, do the following inside a loop:
      1. Ask the user to enter one of their favorite colors and append it to the list colors. Assume they will enter a valid input.
      2. Increment count by 1.
      3. Ask the user if they want to continue They should enter ‘y’ or ‘n’. Assume they will enter a valid input. Save the response and in flag.
   5. After exiting the loop print i) how many colors the user entered and ii) the list of colors entered by the user, if they entered at least 1 color.

Answer 1

PYTHON CODE:

# Counter to count how many colors user has entered
count = 0
# List of colors
colors = []
# Ask user if he wants to enter colors or not
flag = input('Do you want to enter up to 3 favorite colors? (y/n): ')
# Loop till user denies or has entered more than 3 colors
while flag is not 'n' and count < 3:
   # Ask user to enter his favorite color
   color = input('Enter your favorite color: ')
   # Append color to the list of colors
   colors.append(color)
   # Increment counter
   count += 1
   # Ask user if he wants to continue entering colors
   flag = input('Do you want to continue? (y/n): ')

# Print number of colors user has entered
print('The user entered %d colors' % (count))
# If user has entered any color then only print the list of colors
if count > 0:
   print('List of colors:', colors)

SAMPLE OUTPUT: