Import Python Modules/Packages with example

This short article describes how to include the python modules. This will help the python developers to refresh the syntax. 

For detailed articled go to https://docs.python.org/3/tutorial/modules.html#packages

Import a single file:

Lets take a python file say test.py

test.py

def testMod():

    print("In test module")

 To include this file in your python project, 

myPyt.py

#

# My python Project

#

import test

test.testMod()

Output:   

In test module

Import a library (directory of python files):

This concept is called Packaging/Packages.

Lets say library called 'lib' contains two python files 'test1.py' and 'test2.py'. 

lib/test1.py

def test1Mod():

    print("In test1 module")

lib/test2.py

 

def test2Mod():

    print("In test2 module")

Now create a empty file called __init__.py in the directory to be imported which is lib here

touch __init__.py

lib contains the following the files.

__init__.py

test1.py

test2.py

Now simply import this lib into your python file/project:

myPyt.py

#

# My python Project

#

from lib import test1,test2

test1.test1Mod()

test2.test2Mod()

Output:

In test1 module

In test2 module

__init__:

 
The __init__.py file is the one which makes Python treat the directory as a package.

Generally import lib.* will import all the files in lib. To prevent this add a list called __all__ in __init__.py of the package/directory.

__init__.py

__al1__ = ["test1"]

Now 

from lib import  *    will import only test1