Modules

As you start to write larger programs, you will want  to save the function de?nitions in multiple ?les, collected together according to what  they  do.  So, for example, we may  collect a set of utility  functions together into  in one file, called  utility.py.  This ?le is known as  a module in Python.

Now,  if we want  to use  those  procedures in another shell or file,  we will require to say import utility so that  all those  procedures become  available to us and  to the Python interpereter.  Now,  if we have a function in utility.py named foo, we may use it with the name  utility.foo. You may study  more  about  modules, and  how  to instance reference functions described in procedures, in the Python documentation.