How to pass value from method to function

[buran]

I really don't understand your confusion. Your previous post show that you understand how to pass argument to a function.
your function signature should look like this

def list_length(single_method_list)

so it's name must be list_length as that is the name expected by the test case. It takes one argument - single_method_list. It must be instance of SingleMethodList class defined in another module (single_method_list.py file). Note that you should stick to the name of the class as given to you because the test case will try to instantiate variable s_list of this class.