What does += mean in Python?

Question

I see code like this for example in Python:

    if cnt > 0 and len(aStr) > 1:
        while cnt > 0:                  
            aStr = aStr[1:]+a         


        

Answer 1

it means "append "THIS" to the current value"

example:

a = "hello"; a += " world";

printing a now will output: "hello world"