string not contains python string code example

Example 1: if substring not in string python

fullstring = "StackAbuse"
substring = "tack"

if fullstring.find(substring) != -1:
    print "Found!"
else:
    print "Not found!"

Example 2: python string contains

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