how to replace every case of a string in py code example

Example 1: python replace all occurrences in string

>>> 'no one knows how'.replace('no', 'yes')
'yes one kyesws how'

Example 2: python replace char in string

# Python3 program to demonstrate the  
# use of replace() method   
  
string = "geeks for geeks geeks geeks geeks" 
   
# Prints the string by replacing geeks by Geeks  
print(string.replace("geeks", "Geeks"))  
  
# Prints the string by replacing only 3 occurrence of Geeks   
print(string.replace("geeks", "GeeksforGeeks", 3))