how to find word in file python code example

Example 1: how to find word in file python

with open('example.txt') as f:
    if 'blabla' in f.read():
        print("true")

Example 2: python read text file look for string

f = open(filename,  "r")
   whattoReturn = "None"
   if strToFind in f.read():
      whattoReturn = strToFind