Using the 'pydoc' Command (with examples)

The ‘pydoc’ command is a valuable tool for Python developers, providing offline access to Python’s comprehensive documentation directly from the command line. It allows users to inspect the documentation of Python keywords, functions, modules, and packages, and even run a local documentation server to browse through information using a web interface. Pydoc is an essential aid that can boost productivity by offering immediate reference material without needing an internet connection.

Use case 1: Print documentation on a subject (Python keyword, topic, function, module, package, etc.)

Code:

pydoc sorted

Motivation for using the example:

When writing Python code, understanding how a function or keyword operates is crucial to utilizing it effectively. For instance, the sorted function is fundamental for organizing lists. Knowing the parameters it accepts and its behavior can significantly enhance code efficiency and readability. Instead of spending time searching online, developers can instantly retrieve this information using the pydoc command, ensuring productivity and continuity in workflow.

Explanation for every argument given in the command:

• pydoc: This part of the command invokes the Python documentation tool, which is intended to display documentation strings for various Python elements.

• sorted: This argument specifies the name of the subject for which documentation is being queried. In this case, it is the sorted function, which is used to sort iterable elements in Python.

Example output:

Help on built-in function sorted in module builtins:

sorted(iterable, /, *, key=None, reverse=False)
    Return a new list containing all items from the iterable in ascending order.
    
    A custom key function can be supplied to customize the sort order, and the
    reverse flag can be set to request the result in descending order.

Use case 2: Start an HTTP server on an arbitrary unused port and open a browser to see the documentation

Code:

pydoc -b

Motivation for using the example:

Sometimes developers might prefer a more interactive way of browsing Python documentation, similar to navigating a website with hyperlinks and search functionalities. By running pydoc with the -b option, they can start an HTTP server that serves the documentation on a local port, opening it in a web browser. This feature provides an organized and visual interface, making it easier to explore and find specific information without continuously switching between terminal windows.

Explanation for every argument given in the command:

• pydoc: As before, this calls the pydoc tool, facilitating access to Python’s documentation.

• -b: This is an option flag that instructs pydoc to start an HTTP server on an available port and automatically open a new page in the default web browser. The server displays the documentation in a navigable HTML format, making it user-friendly.

Example output:

Upon executing, the following output is displayed in the terminal, indicating the server has started and on which port:

pydoc server ready at http://localhost:41721/

A web browser should automatically open to the above URL, displaying the Python documentation homepage.

Use case 3: Display help

Code:

pydoc

Motivation for using the example:

For new developers or those not familiar with all the functionalities pydoc offers, accessing help directly from the command line is incredibly beneficial. By simply typing pydoc, users can view a help message that outlines the command’s main features and options. This quick reference helps users understand how to utilize pydoc effectively and uncover additional capabilities they may not be aware of.

Explanation for every argument given in the command:

• pydoc: Executing the pydoc command without any additional arguments brings up a help message. This serves as an overview of the command’s functionality, providing usage syntax, available options, and brief descriptions of what each option does.

Example output:

pydoc - the Python documentation tool

pydoc <name> ...
pydoc -k <keyword> ...
pydoc -p <port>
pydoc -b
...

This output provides an at-a-glance overview, enumerating the various modes in which pydoc can be used and giving developers the necessary guidance to proceed with their specific documentation needs.

Conclusion:

The ‘pydoc’ command is a versatile tool that caters to multiple needs in a Python development environment, from providing concise function and module documentation to offering a full-fledged, server-hosted browsing experience for Python’s extensive documentation. Whether you need quick insights into a Python element, a more graphical way to drill down into documentation, or guidance on what pydoc itself can do, these examples demonstrate its flexibility and practicality in supporting efficient programming practices.