Modules in Python

What are Modules in Python? 

Modules are simply a ‘program logic’ or a ‘python script’ that can be used for variety of applications or functions. We can declare functions, classes etc in a module.

A module allows you to logically organize your Python code. Grouping related code into a module makes the code easier to understand and use. A module is a Python object with arbitrarily named attributes that you can bind and reference.

Simply, a module is a file consisting of Python code. A module can define functions, classes and variables. A module can also include runnable code.

How To Create Modules In Python?

Creating a module in python is similar to writing a simple python script using the .py extension. For the above example lets try to make a module for the various operations.

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def add(x,y):      return x + y   def sub(x, y):      return x - y   def prod(x, y):     return x * y   def div(x, y):     return x / y

Save the above code in a file Calc.py. This is how we create a module in python. We have created different functions in this module. We can use these modules in our main file, lets take a look at how we are going to use them in a program.

How To Use Python Modules?

We will use the import keyword to incorporate the module into our program, from keyword is used to get only a few or specific methods or functions from a module. Lets see what are different methods to use a module in your program.

Lets say we have our file with a name main.py.

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import calc as a a = 10 b = 20   addition = a.add(a,b) print(addition)

In the above code, we have created an alias using the as keyword. The output of the above code will be the addition of the two numbers a and b using the logic specified in the add function in the calc.py module.

Lets take a look at another approach.

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from calc import * a = 20 b = 30   print(add(a,b))

In the above code, we have imported all the functions using the asterisk and we can simply mention the function name to get the results. 

Python Module Path

When we import a module, the interpreter looks for the module in the build-in modules directories in sys.path and if not found, it will look for the module in the following order:

1. Current directory
2. PYTHONPATH
3. Default directory

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import sys   print(sys.path) To add Your file path to the system path.You can use m_directory="home/python_files" sys.path.append(m_directory) #

When you run the above code, you will get the list of directories. You can make changes in the list to create your own path.