PrettyPrinter is a powerful and expressive library for formatting and printing Python objects, designed for Python 3.6 and above. It uses an enhanced version of the Wadler-Leijen layout algorithm, similar to the prettyprinter in Haskell’s libraries, as well as tools like anti-wl-pprint, JavaScript's Prettier, Ruby's prettypreinter.rb, and IPython's Ipython.lib.pretty. Building on the strengths of these tools, PrettyPrinter has been refined to offer superior formatting capabilities, making it the most advanced tool for structured output in Python.
Here’s a screenshot of the output using PrettyPrinter:
Why does Python need a better printing tool?
Printing data to the console is one of the most fundamental interactions during development. Improving this interface can significantly enhance productivity and the overall developer experience. While Python and third-party libraries already provide some tools for this purpose, they often fall short in terms of flexibility and readability.
The built-in `__repr__` and `__str__` methods return simple strings, but they lack the ability to format or beautify output. The standard `pprint` module offers basic formatting for built-in types, but its greedy layout algorithm can lead to suboptimal results. Third-party alternatives like `pprintpp` improve on this, but still rely heavily on `__repr__`, limiting their usefulness with custom classes.
IPython's `IPython.lib.pretty` is more advanced, offering better formatting and customization options. However, it requires understanding of internal layout algorithms and has some API limitations that can interfere with the normal flow of data processing.
These tools didn't meet my needs, so I developed PrettyPrinter to address those shortcomings. It focuses on providing clean, readable output without sacrificing performance. Even if it takes a fraction of a second longer to format, it saves time when debugging large outputs.
PrettyPrinter also introduces a simple, descriptive API for defining custom formatting rules. Unlike `__repr__`, which is painful to override, the API makes it easy to define how your objects should be displayed. Additionally, it includes syntax highlighting that works even with invalid Python syntax, ensuring a consistent and visually appealing output.
One of the most exciting features is the ability to annotate instances with state information. This allows you to add comments or descriptions directly to your objects, making the output more informative and easier to understand.
For example, you can define how a custom class should be printed by registering a pretty function:
```python
register_pretty(MyClass, lambda obj, ctx: pretty_call(obj, ctx))
```
This enables full control over how your objects are displayed, making debugging and inspection much more efficient.
In conclusion, I highly recommend trying PrettyPrinter. It integrates seamlessly with IPython and provides a much better experience than traditional printing methods. Whether you're working in a script or an interactive environment, it makes inspecting complex data structures much easier. You can find the source code on GitHub and detailed documentation on Read the Docs. If you use Django models, QuerySets, or the `attrs` package, you'll find that PrettyPrinter comes with built-in support—making it a must-have tool for any Python developer.
USB4 80Gbps Data Cable
Usb4 80Gbps Data Cable,Tpe Pd Fast Cherger Cable,Thunderbolt4 80Gbps Data Cable,High-Speed Data Cable
Dongguan Pinji Electronic Technology Limited , https://www.iquaxusb4cable.com