I have split the code into multiple files. I have imported all the functions from all other files into admin.py. Lets say I want to call a function XYZ. If I give path to function as admin/XYZ it gives me error as invalid function and for this I have to give the path as file_with_XYZ_function/XYZ.
Is there a way to overcome this problem and simple call all the imported functions from one single file
you can create python files in modules folder and import them just like how you import python libraries in your controllers. But you have to give the path to those files like 
 from applications.myApp.modules.myModule import *
this is my solution for my wrappers. now you can use your functions by calling their name
myFunction
Function call using import in web2py