python check if string contains more characters code example

Example 1: how to check if all characters in string are same python

s == len(s) * s[0]

Example 2: how to check if a string contains a word python

if word in mystring: 
   print('success')

Example 3: python check if string contains one of characters list

if any(ext in url_string for ext in extensionsToCheck):
    print(url_string)