pyton, check if string contains code example

Example 1: how to check if there is a word in a string in python

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

Example 2: how to check for a substring in python

def find_string(string,sub_string):
	return string.find(sub_string)
#.find() also accounts for multiple occurence of the substring in the given string