A module is a Python file that contains functions, definitions, and statements that can be included in other files within an application. Technically, all files with the
.py format are modules.
Conceptually, modules are named units of code that can be reused across applications and allows us to access shared libraries (collections of modules) and packages (modules with nested modules and packages). Instead of entering commands directly into a Python interpreter, code can be saved as a module for later use in other applications.
Creating and Importing Modules
A module can be created by saving a Python file with the
.py file extension. It can then be imported into another
.py file with an
For example, a separate
video_player.py file that was previously saved can be imported in other files:
import video_player# Rest of the program starts here...
The program now has access to all functions, objects, and statements contained within the
Importing Specific Resources
Instead of importing the whole module, individually named resources can be specified. For example:
from video_player import VideoPlayer
This will import only the
VideoPlayer class from a given
video_player module, rather than all types of collections contained within it.
It’s often useful to import only what is needed to avoid slowing the program down and polluting the local namespace where the code runs.
Namespaces and Scope
A module within our local namespace can be renamed by creating an alias using the
as keyword. For example:
from bs4 import BeautifulSoup as bs
Aliasing is especially convenient for shortening module names and managing the local namespace where our code executes.
Once a module is imported, it is within the scope of the program and it can be accessed in the local namespace.
Python Standard Modules
Python comes with several different built-in modules that provide a variety of functions. They include:
collectionsmodule provides additional collection types.
functoolsmodule provides functions supporting a functional programming approach.
globmodule allows matching file paths per Unix shell rules.
jsonmodule provides functions for dealing with JSON objects.
mathmodule provides useful mathematical functions.
randommodule provides functions for dealing with random numbers.
timemodule provides various functions for dealing with time.
Python Third-Party Modules
Python has a very broad selection of third-party modules that are devoted to particular tasks.
These are third-party Python modules that have topic entries:
- NumPy: a popular open-source Python library used for complex mathematical operations and multi-dimensional arrays.
- Pandas: a popular open-source Python module used for data analysis and manipulation.
Below is a selection of other third-party modules of note:
- A Python API for Apache Spark, consisting of several modules.
- An open-source framework that offers an optimized tensor library for deep learning.
- A module that allows the generation of progress bars in Python.