Is there a built-in Python function which will return the first True-ish value when mapping a function over an iterable?

Question

Here\'s the functionality I mean, and I do it pretty frequently so maybe I\'m just reimplementing a built-in that I haven\'t seen:

import itertools
def first         


        

Answer 1

you can use next() builtin and generator expression:

next(example[key] 
        for key in ['dolphin', 'guide', 'answer', 'panic', 'bring'] 
        if key in example)

if you want to use predefined function, it might be better to use filter, which accepts function as the first argument (lambda in example):

next(itertools.ifilter(lambda txt: 'a' in txt, ['foo', 'bar']))