zip function

iam struggling for writing zip function in python.actually i wrote once this zip very long time back.meanwhile i forget the whole concept. Again iam trying to write a zip function with basic knowledge of python.

I think this called unlearning. i don't know exactly what is unlearning.

actually i written zip function using Python builtin function called map.what map does is
"it takes any number of arguments,but first argument should be function and remaining arguments should be lists.it return a list of the results of applying the function to the items of the argument sequence or sequences. If more than one sequence is given, the function is called with an argument list consisting of the corresponding item of each sequence, substituting None for missing values when not all sequences have the same length. If the function is None, return a list of the items of the sequence."