Why use Pygame: If you think anyone outside of the game development world would ever bother with such a framework, think again. Pygame is a handy way to work with many GUI-oriented behaviors that might otherwise demand a lot of heavy lifting: drawing canvas and sprite graphics, dealing with multichannel sound, handling windows and click events, detecting collisions, and so on. Not every app—or even every GUI app—will benefit from being built with Pygame, but you ought to take a close look at what Pygame provides. You might be surprised!
Pyglet
What Pyglet does: Cross-platform multimedia and window graphics in pure Python.
Why use Pyglet: Pyglet provides handy access to items that are tedious to implement from scratch for a GUI application: window functions, OpenGL graphics (shader support is being added), audio and video playback, keyboard and mouse handling, and working with image files. Note that Pyglet doesn’t provide UI widgets like buttons, toolbars, or menus, though.
All of this is done through the native platform capabilities in Windows, OS X, or Linux, so there are no binary dependencies; Pyglet is pure Python. It’s also BSD-licensed, so it can be included in any commercial or open source project.
PyInstaller
What PyInstaller does: Package a Python script as a stand-alone executable.
Why use PyInstaller: A common complaint with Python is that it’s harder than it ought to be to distribute a script to other users. PyInstaller lets you package any Python script—even scripts that include complex third-party modules with binaries, like NumPy—and distribute it as a single-folder or single-file application. PyInstaller tends to pack more into that folder or file than is really needed, so the final results can be bulky. But that tendency can be overcome with practice, and the sheer convenience PyInstaller provides is hard to beat.
Note that despite the name, PyInstaller does not create an installer or setup script for your packaged application. A third-party project like NSIS can bridge that gap, though.
PySimpleGUI
What PySimpleGUI does: Creating GUIs in Python with a minimum of fuss.
Why use PySimpleGUI: Python ships with the Tkinter library for creating GUIs, but Tkinter is not known for being easy to work with. PySimpleGUI wraps Tkinter with APIs that are far less exasperating. Many common effects, like a simple dialog box or pop-up menu, can be accomplished in a single line of code. The interfaces still have Tkinter’s trademark look, though. If you want a more sophisticated look and feel you’ll need to look elsewhere.
Python-docx
What Python-docx does: Programmatically manipulate Microsoft Word .docx files.
Why use Python-docx: In theory, it should be easy to write scripts that create and update XML-style Microsoft Word documents. In practice, it is far from simple, due to all of the internal complexities of the .docx format. Python-docx lets you do an end run around all of those complexities, by providing a high-level API for working with .docx files.
Python-docx lets you add or change text, images, tables, styles, document sections, and headers and footers. The library allows you to create new documents or change existing documents. Python-docx is a great way to pull raw text from Word files, or to avoid dealing with Word’s own built-in automation functions.
Scrapy
What Scrapy does: Screen scraping and web crawling.
Why use Scrapy: Scrapy makes scraping simple. Create a class that defines the items you want scraped and write some rules to extract that data from the page. The results can be exported as JSON, XML, CSV, or any number of other formats. The collected data can be saved raw or sanitized as it is imported.
Scrapy can be extended to handle many other tasks, such as logging into a website and handling session cookies. Images, too, can be scraped up by Scrapy and associated with the captured content. The latest versions improve Scrapy’s ability to work with cloud services such as Amazon S3 and Google Cloud Storage to store scraped data.
Sh
What Sh does: Call any external program, in a subprocess, and return the results to a Python program—using the same syntax as if the program in question were a native Python function.
Why use Sh: On any POSIX-compliant system, Sh is a godsend, allowing any command-line program available on that system to be used Pythonically. Not only are you freed from having to reinvent the wheel (why implement ping when it’s right there in the OS?), but you no longer have to struggle with adding that functionality elegantly to your application. However, be forewarned: Sh provides no sanitization of the parameters that are passed through. Be sure never to pass along raw user input.
Splinter
What Splinter does: Test web applications by automating browser actions.
Why you need it: Let’s face it, trying to automate web application testing is no one’s idea of fun. Splinter eliminates the low-level grunt work, invoking the browser, passing URLs, filling out forms, clicking buttons, and so on, automating the whole process from end to end.
Splinter provides drivers to work with Chrome and Firefox, and it can use Selenium Remote to control a browser running elsewhere. You can even manually execute JavaScript in the target browser.