checking an input is a single letter in python

Question

im trying to check that the input the user enters is either a single letter or word and not an integer or nothing, if they enter something which isnt valid then they should be kept in the loop until they enter a single letter. this is my code so far but it doesnt seem to be working in the desired way:

animalcount = 0
animal = 0
data = False
while data == False:
    try:
        letter = str(input("what letter would you like to search for? "))
        data = True
    except:
        print ("please enter a letter, try again.")
    if letter == "":
        print ("please enter an item,try again!")
        data = False
for animal in animallist:
    if letter in animal:
        print(animal)
        animalcount = animalcount + 1
if animalcount == 0:
    print ("That letter cannot be found")

What is the problem exactly? Are you on python2.x or python3.x? — mgilson, Feb 07 '13 at 14:45
http://stackoverflow.com/questions/510357/python-read-a-single-character-from-the-user — ogzd, Feb 07 '13 at 14:45

score 1 · Answer 1 · answered Feb 07 '13 at 14:53

1

Making a string from input will not achieve much since anything you enter with the keyboard will work perfectly fine as a string.

You could use a regexp to distinguish between letters and numbers.

answered Feb 07 '13 at 14:53

Jonatan

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score 0 · Answer 2 · answered Feb 07 '13 at 14:58

0

You could just use a simple loop at the top.

import string
letter = None
while not letter or letter not in string.letters:
    letter = str(raw_input("What letter would you like to search for? "))

Then the rest should work.

answered Feb 07 '13 at 14:58

sotapme

4,695
2
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checking an input is a single letter in python

2 Answers2