how to detect certain strings within strings in python code example

Example 1: python str contains word

fullstring = "StackAbuse"
substring = "tack"

if substring in fullstring:
    print "Found!"
else:
    print "Not found!"

Example 2: check if string contains python

>>> str = "Messi is the best soccer player"
>>> "soccer" in str
True
>>> "football" in str
False