Can I create a module myself or they are predefined?

Answer 1

You can create your own modules :D you just have to save your code in an other file and you can also make your own library.

Answer 2

I am also learning python here....
so by the knowledge it got ...I can say that modules are pre defined in library of python...
you can also make them ..
But you should be a professional developer and know how to create them you can make them of your own