CSCI 1470: introduction

Introduction to Python's Modules
CSCI 1470

by K. Yue

1. Introduction to Python's Modules

A module is a file containing Python definitions and statements.
The file name is the module name with the suffix .py appended as the file extension. Examples: sys.py, turtle.py, wikipedia.py
Documentation: https://docs.python.org/3/tutorial/modules.html.
There are many advantages of using Python modules:
1. Code reusability: uses Python code developed and tested by experienced Python developers.
2. Code organization: allows local grouping of related code into files.
3. Other advantages...
The Python program being executed is known as the main module.
A module can use other modules by importing them.
"Within a module, the module’s name (as a string) is available as the value of the global variable __name__."

A Python package is a way to organize related modules into a directory hierarchy.

1.1 Built-in Python modules

Built-in Python modules are pre-installed Python modules that come with the Python installation.
It can be regarded as Python's standard library.
Users do not need to install built-in Python modules themselves. They are already there.
To manage and access Python modules effectively, they are stored in specific folders (usually the Lib sub-directory of the Python installation.
Example:

2. External Python modules and Python

External Python modules are modules not come with Python standard library.
They are also known as third party modules.
Packages containing these external Python modules need to be downloaded and properly installed before using.
pip (Pip Installs Packages) is the python program for installing and managing Python packages.

Use "pip install <<module_to_be_install>>" in a command prompt to install a package.
The Python Package Index (PyPI) is the official repository for Python software packages.
When using "pip install wikipedia" (for example), pip will check PyPI for the package wikipedia, and then download, unpack and install the package.

Examples:

pip3.13 install numpy
pip3.12 install numpy
pip3 install scipy
pip install wikipedia