Determining if a string contains a word [duplicate]

Answer 1

words = 'blue yellow'

if 'blue' in words:
    print 'yes'
else:
    print 'no'

Edit

I just realized that nightly blues would contain blue, but not as a whole word. If this is not what you want, split the wordlist:

if 'blue' in words.split():
    …

Answer 2

You can also use regex:

\bblue\b will return True only if it can find the exact word 'blue', otherwise False.

In [24]: import re

In [25]: strs='blue yellow'

In [26]: bool(re.search(r'\bblue\b',strs))
Out[26]: True

In [27]: strs="nightly blues"

In [28]: bool(re.search(r'\bblue\b',strs))
Out[28]: False

Answer 3

You can use in or do explicit checks:

if 'blue ' in words:
    print 'yes'

or

if words.startswith('blue '):
    print 'yes'

Edit: Those 2 will only work if the sentence doesnt end with 'blue'. To check for that, you can do what one of the previous answers suggested

if 'blue' in words.split():
    print 'yes'

Answer 4

The easiest way to do this is probably the following:

words = set('blue yellow'.split())
if 'blue' in words:
    print 'yes'
else:
    print 'no'

If your words list is really huge, you'll get a speed increase by wrapping words.split() in set as testing set membership is more computationally efficient than testing list membership.