Python : String Replace

I have a string with code. It’s not working to replace TestData using .replace

class_text = r"""
@classmethod
def setUpClass(cls):
    #Run base class' setup and then load the web app and login
    super(TestData, cls).setUpClass() 
"""

className = "Test"
class_text.replace("TestData", className)

>Solution :

You should use:

class_text = class_text.replace("TestData", className)

instead of

class_text.replace("TestData", className)

since .replace changes nothing but returns a new string.