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Importing Python Modules

Overview​

This document describes how to import another Python module in your project so that you can use its functions in other location.

This document assumes that your project has the following hierarchy:

myproject/
├── README.md
├── requirements.txt
├── main.py
├── modules/
│   ├── __init__.py
│   ├── module1.py
│   └── subpackage/
│       ├── __init__.py
│       ├── module2.py
└── tests/
    ├── __init__.py
    ├── test_module1.py
    └── subpackage/
        ├── __init__.py
        ├── test_module2.py

In this example, the top-level myproject directory contains a subdirectory called modules, which contains your Python module module1.py.

The subpackage subpackage contains the module module2.py.

The __init__.py file is an empty file that tells Python the modules directory should be treated as a package.

Subpackage:

To make your module importable from other parts of your project, place it in the appropriate directory within your package.

If your module is a top-level module (i.e., not part of a subpackage), you can place it directly in the main package directory (modules). If it's part of a subpackage, you should place it in the appropriate subdirectory within the package directory.

This document assumes that your module1.py and module2.py define the functions my_function_1 and my_function_2 below:

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

# module 1 function
def my_function_1():
    print("Module 1")
#!/usr/bin/env python3
# -*- coding: utf-8 -*-

# module 2 function
def my_function_2():
    print("Module 2")

Import an Entire Module​

To import the whole module1.py module from other parts of your project, use the dot notation as follows:

import modules.module1

To import the whole module2.py module:

import modules.subpackage.module2

With this import statement, all functions from the module can be imported.

Import a Specific Function​

To import a specific function from a module:

from modules.module1 import my_function_1
from modules.subpackage.module2 import my_function_2

You can also import more functions if needed:

from modules.module1 import my_function_1 my_another_function

Give a function an alias​

Sometimes the function name can be too long or duplicates with another function name. In this case, you can give your function an alias:

from modules.module1 import my_function_1 as alias_1

In this way, you can call my_function_1 using alias_1.

Give a module an alias​

Similarly, you can also give your module an alias:

import module1 as module_1

With this import statement, you can call module1 using module_1.

Import all functions in a module​

To import all the functions in a module, use the asterisk (*) in the import statement:

from module1 import *

Running Python scripts in Bash scripts​

To use your python modules in a bash script, you can't use the import statement. Instead, use the python module1.py command in your script:

python module1.py