#253: A new Python for you, and for everyone!

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About the show

Special guest: Yael Mintz

Sponsored by us:

• Check out the courses over at Talk Python
• And Brian’s book too!

Michael #1: awesome-htmx

• An awesome list of resources about htmx such as articles, posts, videos, talks and more.
• Good for all sorts of examples and multiple languages
• We get a few nice shoutouts, thanks

Brian #2: Python 3.10 is here !!!!

• As of Monday. Of course I have it installed on Mac and Windows. Running like a charm.
• You can watch the Release Party recording. It’s like 3 hours. And starts with hats. Pablo’s is my fav.
• Also a What’s New video which aired before that with Brandt Bucher, Lukasz Llanga ,and Sebastian Ramirez (33 min)
  • Includes a deep dive into structural pattern matching that I highly recommend.
• Reminder of new features:
  • PEP 623 -- Deprecate and prepare for the removal of the wstr member in PyUnicodeObject.
  • PEP 604 -- Allow writing union types as X | Y
  • PEP 612 -- Parameter Specification Variables
  • PEP 626 -- Precise line numbers for debugging and other tools.
  • PEP 618 -- Add Optional Length-Checking To zip.
  • bpo-12782: Parenthesized context managers are now officially allowed.
  • PEP 632 -- Deprecate distutils module.
  • PEP 613 -- Explicit Type Aliases
  • PEP 634 -- Structural Pattern Matching: Specification
  • PEP 635 -- Structural Pattern Matching: Motivation and Rationale
  • PEP 636 -- Structural Pattern Matching: Tutorial
  • PEP 644 -- Require OpenSSL 1.1.1 or newer
  • PEP 624 -- Remove Py_UNICODE encoder APIs
  • PEP 597 -- Add optional EncodingWarning
• Takeaway I wasn’t expecting: black doesn’t handle Structural Pattern Matching yet.

Yael #3: Prospector (almost) All Python analysis tools together

• Instead of running pylint, pycodestyle, mccabe and other separately, prospector allows you to bundle them all together
• Includes the common Pylint and Pydocstyle / Pep257, but also some other less common goodies, such as Mccabe, Dodgy, Vulture, Bandit, Pyroma and many others
• Relatively easy configuration that supports profiles, for different cases
• Built-in support for celery, Flask and Django frameworks
• https://soshace.com/how-to-use-prospector-for-python-static-code-analysis/

Michael #4: Rich Pandas DataFrames

• via Avi Perl, by Khuyen Tran
• Create animated and pretty Pandas Dataframe or Pandas Series (in the terminal, using Rich)
• I just had Will over on Talk Python last week BTW: Terminal magic with Rich and Textual
• Can limit rows, control the animation speed, show head or tail, go “full screen” with clear, etc.
• Example:

      from sklearn.datasets import fetch_openml
      from rich_dataframe import prettify
  
      speed_dating = fetch_openml(name='SpeedDating', version=1)['frame']
      table = prettify(speed_dating)
  

Brian #5: Union types, baby!

• From Python 3.10: “PEP 604 -- Allow writing union types as X | Y”
• Use as possibly not intended, to avoid Optional:

      def foo(x: str | None = None) -> None:
        pass 
  

• 3.9 example:

      from typing import Optional
      def foo(x: Optional[str] = None) -> None:
        pass
  

• But here’s the issue. I need to support Python 3.9 at least, and probably early, what should I do?
• For 3.7 and above, you can use from __future__ import annotations.
• And of course Anthony Sottile worked this into pyupgrade and Adam Johnson wrote about it:
  • Python Type Hints - How to Upgrade Syntax with pyupgrade
• This article covers:
  • PEP 585 added generic syntax to builtin types. This allows us to write e.g. list[int] instead of using typing.List[int].
  • PEP 604 added the | operator as union syntax. This allows us to write e.g. int | str instead of typing.Union[int, str], and int | None instead of typing.Optional[int].
  • How to use these. What they look like. And how to use pyupgrade to just convert your code for you if you’ve already written it the old way. Awesome.

Yael #6: Make your code darker - Improving Python code incrementally

• The idea behind Darker is to reformat code using Black (and optionally isort), but only apply new formatting to regions which have been modified by the developer
• Instead of having one huge PR, darker allows you to reformat the code gradually, when you're touching the code for other reasons..
• Every modified line, will be black formatted
• Once added to Git pre-commit-hook, or added to PyCharm **/ VScode the formatting will happen automatically

Extras

Brian:

• I got a couple PRs accepted into pytest. So that’s fun:
  • 9133: Add a deselected parameter to assert_outcomes()
  • 9134: Add a pythonpath setting to allow paths to be added to sys.path
  • I’ve tested, provided feedback, written about, and submitted issues to the project before. I’ve even contributed some test code. But these are the first source code contributions.
  • It was a cool experience. Great team there at pytest.

Michael:

• New htmx course: HTMX + Flask: Modern Python Web Apps, Hold the JavaScript
• auto-optional: Due to the comments on the show I remembered to add support for Union[X, None] and python 10’s X | None syntax.
• Coverage 6.0 released
• Django 3.2.8 released

Yael:

• data-oriented-programming - an innovative approach to coding without OOP, with an emphasis on code and data separation, which simplifies state management and eases concurrency
• Help us to make Cornell awesome 🙂 - contributors are warmly welcomed

Joke: Pair CAPTCHAing