Simple input loop

read.py

"""
Simple input loop thing!

By Lambda Fairy (github.com/lfairy)

Examples::

    n = read(int, 'Enter a number: ')

    MIN = 1
    MAX = 100
    guess = read(
        int_in_range(MIN, MAX),
        'Enter a number from {} through {}: '.format(MIN, MAX))

    true = read(yes_no, 'Do you like ducks? ')

Public domain, because public domain is cool.

"""

def read(parse, message='', error=None):
    while True:
        try:
            return parse(input(message).strip())
        except Exception as ex:
            print(error or ex)

def int_in_range(low, high):
    def parse(s):
        number = int(s)
        if not (low <= s <= high):
            raise ValueError('number must be from {} through {}'.format(low, high))
        return number
    return parse

YESES = set('yt')
NOESES = set('nf')
def yes_no(s):
    if len(s) < 1:
        raise ValueError('enter yes or no')
    letter = s[0].lower()
    if letter in YESES:
        return True
    elif letter in NOESES:
        return False
    else:
        raise ValueError('enter yes or no')