Python: If An Entry Is Not An Acceptable Parameter For A Prompt, How To Re-ask

Im only comfortable with for loops at the moment so I've tried what I can there with minimal success. If I asked the user if they want A, B, or C and the user inputs D, instead of

Solution 1:

Here is an anonymous function that does what you want.

def get_user_choice(prompt, choices):
    while True:
        choice = raw_input(prompt)
        if choice in choices:
            return choice
        else:
            print 'choice must be in: {}'.format(choices)

Using it:

>>> get_user_choice('choose an option in A, B, C: ', ['A', 'B', 'C'])
choose an option in A, B, C: A
'A'
>>> get_user_choice('choose an option in A, B, C: ', ['A', 'B', 'C'])
choose an option in A, B, C: D
choice must be in: ['A', 'B', 'C']
choose an option in A, B, C: B
'B'

Note: I have not given too much information to help you, because I believe you should figure most of this out on your own, but meanwhile you should have some kind of working solution.

Solution 2:

Or this

answers = ['a', 'b','c']

while True:
    user_input = raw_input("Input> ")
    if user_input in answers:
        break

print "'{0}'' has been chosen".format(user_input)