{"id":531,"date":"2020-10-14T02:25:15","date_gmt":"2020-10-14T02:25:15","guid":{"rendered":"https:\/\/www.pythontutorial.net\/?page_id=531"},"modified":"2025-03-30T10:12:38","modified_gmt":"2025-03-30T10:12:38","slug":"python-packages","status":"publish","type":"page","link":"https:\/\/www.pythontutorial.net\/python-basics\/python-packages\/","title":{"rendered":"Python Packages"},"content":{"rendered":"\n

Summary<\/strong>: in this tutorial, you learn about the Python packages and how to use them to structure your application.<\/p>\n\n\n\n

Introduction to Python packages #<\/a><\/h2>\n\n\n\n

Suppose that you need to develop a large application that handles the sales process from order to cash.<\/p>\n\n\n\n

The application will have many modules<\/a>. When the number of modules grows, it’ll become difficult to keep all of them in one location.<\/p>\n\n\n\n

And you may want to group modules into something meaningful.<\/p>\n\n\n\n

This is where packages come into play.<\/p>\n\n\n\n

Packages allow you to organize modules in the hierarchical structure.<\/p>\n\n\n\n

The way Python organizes packages and modules like the Operating System structures the folders and files.<\/p>\n\n\n\n

To create a package, you create a new folder and place the relevant modules in that folder.<\/p>\n\n\n\n

To instruct Python to treat a folder containing files as a package, you need to create a __init__.py<\/code> file in the folder.<\/p>\n\n\n\n

Note that starting with Python 3.3, Python introduced the implicit namespace packages feature. This allows Python to treat a folder as a package without the __init__.py<\/code>.<\/p>\n\n\n\n

For example, the following picture shows the sales<\/code> package that contains three modules including order<\/code>, delivery<\/code>, and billing<\/code>:<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

<\/p>\n\n\n\n

Importing packages #<\/a><\/h2>\n\n\n\n

To import a package, you use the import<\/code> statement like this:<\/p>\n\n\n

import<\/span> package.module<\/code><\/span>Code language:<\/span> Python<\/span> (<\/span>python<\/span>)<\/span><\/small><\/pre>\n\n\n
And to access an object from a module that belongs to a package, you use the dot notation:<\/p>\n\n\n
package.module.function<\/code><\/span>Code language:<\/span> Python<\/span> (<\/span>python<\/span>)<\/span><\/small><\/pre>\n\n\n
The following shows how to use functions in the order<\/code>, delivery<\/code>, and billing<\/code> modules from the sales<\/code> package:<\/p>\n\n\n
# main.py<\/span>\nimport<\/span> sales.order\nimport<\/span> sales.delivery\nimport<\/span> sales.billing\n\n\nsales.order.create_sales_order()\nsales.delivery.create_delivery()\nsales.billing.create_billing()<\/code><\/span>Code language:<\/span> Python<\/span> (<\/span>python<\/span>)<\/span><\/small><\/pre>\n\n\n
To make the code more concise, you can use the following statement to import a function from a module:<\/p>\n\n\n
from<\/span> <module> import<\/span> <function><\/code><\/span>Code language:<\/span> Python<\/span> (<\/span>python<\/span>)<\/span><\/small><\/pre>\n\n\n
For example:<\/p>\n\n\n
# main.py<\/span>\nfrom<\/span> sales.order import<\/span> create_sales_order\nfrom<\/span> sales.delivery import<\/span> create_delivery\nfrom<\/span> sales.billing import<\/span> create_billing\n\n\ncreate_sales_order()\ncreate_delivery()\ncreate_billing()<\/code><\/span>Code language:<\/span> Python<\/span> (<\/span>python<\/span>)<\/span><\/small><\/pre>\n\n\n
It’s possible to rename the object when importing it:<\/p>\n\n\n
# main.py<\/span>\nfrom<\/span> sales.order import<\/span> create_sales_order as<\/span> create_order\nfrom<\/span> sales.delivery import<\/span> create_delivery as<\/span> start_delivery\nfrom<\/span> sales.billing import<\/span> create_billing as<\/span> issue_billing\n\n\ncreate_order()\nstart_delivery()\nissue_billing()<\/code><\/span>Code language:<\/span> Python<\/span> (<\/span>python<\/span>)<\/span><\/small><\/pre>\n\n\n
In this example, we rename…<\/p>\n\n\n\n