Python Language Modularization
External
Internal
Overview
Python Script
A script is a module whose aim is to be executed. It has the same meaning as "program" or "application", but it is usually used to describe simple and small program. It contains a stored set of instructions that can be handed over to the Python interpreter. Python scripts have .py extensions.
Top-Level Script
Packages can be run as if they were scripts if the package provides a top-level script __main__.py.
- TO PROCESS: https://docs.python.org/3/library/__main__.html
- Understand setup.py - it defines the entry point.
Standalone Program
Module
A module is an organizational unit of Python code. It is a file with the .py extension containing Python code that can be imported inside another Python program. It can define functions, classes and variables. A module can also include runnable code. The file name is the module name with the suffix .py appended. Modules have a namespace containing arbitrary Python objects. Modules are loaded into Python by the process of importing, where the code in one module is made available to Python code in another module.
Does this apply to module?
import pulumi_aws as aws
aws.ec2.SecurityGroup(....)
Notable Modules
- venv
- What is the difference between a standard library and a module.
- "webbrowser" standard library.
Package
A package is a Python module which can contain submodules or recursively, subpackages. Technically, a package is a Python module with a __path__ attribute. Packages allow for a hierarchical structuring of the module namespace using dot notation. In the same way that module avoid collisions between global variable names, packages avoid collision between module name. Packages are managed by a Python package manager like pip, Conda, Pipenv and Poetry.
Python Package Index PyPI
It can be searched with pip search.
Regular Package
A traditional package, such as a directory containing an __init__.py file.
Namespace Package
A PEP 420 package which serves only as a container for subpackages. Namespace packages may have no physical representation, and have no __init__.py file.
Package Metadata
Name: pulumi
Version: 2.11.2
Summary: Pulumi's Python SDK
Home-page: https://github.com/pulumi/pulumi
Author:
Author-email:
License: Apache 2.0
Location: /Users/ovidiu/Library/Python/3.8/lib/python/site-packages
Requires: dill, grpcio, protobuf
Required-by: pulumi-aws, pulumi-kubernetes, pulumi-random, pulumi-tls
Requires
Required-by
Importing a Package
Clarify the difference between importing a module and a package.
import mypackage
TO PROCESS: The import system: https://docs.python.org/3/reference/import.html
Library
The term library is simply a generic term for a bunch of code that was designed with the aim of being reused by many applications. It provides some generic functionality that can be used by specific applications. When a module or a package is published, people refer to it as a library.
Standard Library
If the published module or package is is available in the Python Module Index, it is referred to as a "standard library".
Python Standard Library
Contains the Python Module Index.