Mailman 3 - Python-ideas

Add a .whitespace property to module unicodedata
by Antonio Carlos Jorge Patricio June 1, 2023

June 1, 2023

I suggest including a simple str variable in unicodedata module to mirror string.whitespace, so it would contain all characters defined in CPython function [_PyUnicode_IsWhitespace()](https://github.com/python/cpython/blob/main/Obje… so that: # existent string.whitespace = ' \t\n\r\x0b\x0c' # proposed unicodedata.whitespace = ' \t\n\x0b\x0c\r\x1c\x1d\x1e\x1f\x85\xa0\u1680\u2000\u2001\u2002\u2003\u2004\u2005\u2006\u2007\u2008\u2009\u200a\u2028\u2029\u202f\u205f\u3000'

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Virtual packages
by Soni L. May 21, 2023

May 21, 2023

Python allows setting __path__ to turn a module into a package. However, it's allegedly only defined for __init__.py? Proposal: A virtual package is a non-__init__.py whose first line of code, after comments and future imports, assigns to __path__. This would allow -m virtualpackage to call virtualpackage.__main__, wherever that is. Instead of running virtualpackage.py as __main__.

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Visual Python.
by Michael R May 19, 2023

May 19, 2023

To whom it may concern: Is it possible to create a Visual Python with options and editing tools similar to Excel? In the beginning it could be a combo with a command-docker, calling for a visual Routine. Indented structure of coding in Python is perfectly suited for it. In my mind such structure was the first subconscious step in this direction. It would make programming much easier: almost like playing with LEGO blocks. Sincerely, Michael R.

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@lazy decorator an alternative to functools.partial ?
by Daniel Guffey May 18, 2023

May 18, 2023

Hello all! I've been playing with string templating quite a bit lately and wrote some logic to help me with this. I found it a bit more flexible than using partial and wanted to get feedback to see if it would be worth formalizing this code into the functools module. It's pretty short so I don't think it deserves its own module, and it behaves similarly to partial but has a bit more flexibility. Thanks for your time! ```python from functools import wraps from typing import Any, Callable, … [View More]Union def lazy(func: Callable[..., Any]) -> Callable[..., Any]: """ A decorator that buffers args and kwargs gathering and function execution suspending processing until the function is called without any args or kwargs. This allows any function to support partials for decomposition out of the box. Also, supports variable length arguments and kw_arguments. Example: import math @lazy def velocity(height_m: float, acceleration_m2: float) -> float: return math.sqrt(2 * acceleration_m2 * height_m) g = -9.81 # acceleration due to gravity in m/s^2 earth = velocity(acceleration=g) v = earth(height=1)() print("The velocity is:", v, "m/s") v = earth(height=10)() print("The velocity is:", v, "m/s") v = earth(height=100)() print("The falling velocity is:", v, "m/s") """ @wraps(func) def collect(*args: Any, **kwargs: Any) -> Any: if not args and not kwargs: return func(*args, **kwargs) return ( lambda *next_args, **next_kwargs: func( *(args + next_args), **{**kwargs, **next_kwargs} ) if not next_args and not next_kwargs else collect(*(args + next_args), **{**kwargs, **next_kwargs}) ) return collect @lazy def f_string_head(f_str: str, **kwargs) -> Union[Callable[[], str], str]: """ Turns an f-string into a curry-able function, will return head to end or first KeyError when finally evaluated with no arguments. """ try: results = f_str.format_map({} if kwargs is None else kwargs) return results except KeyError as e: sub_template = f_str.split("{" + e.args[0] + "}", 1)[0] results = sub_template.format_map({} if kwargs is None else kwargs) return results def test_f_string() -> None: """ Tests the f_string function. """ template = """{one}{two}{three}""" f_one = f_string_head(template, one="1") f_one_three = f_one(three="3") f_one_two_three = f_one_three(two="2") assert f_one() == "1" assert f_one_three() == "1" assert f_one_two_three() == "123" def test_curring() -> None: @lazy def my_function(*args, **kwargs): print( "Function evaluated with arguments:", args, "and keyword arguments:", kwargs ) assert args == (1, 2, 3, 4) assert kwargs == {"a": 2, "b": 5} return "Function passed" partial_function = my_function(1, 2, a=3) result = partial_function(3, 4, b=5, a=2) results = result() print(results) def test_add() -> None: @lazy def add(*args: int, **kwargs: int) -> int: """ A function that takes any number of integer arguments and returns their sum. Args: *args: Integer arguments to be summed. **kwargs: Integer keyword arguments to be summed. Returns: The sum of the integer arguments. """ return sum(args) + sum(kwargs.values()) result = add(1)(2, 3)(4)(5, six=6)() print(f"Add={result}") def test_velocity() -> None: import math @lazy def velocity(height_m: float, acceleration_m2: float) -> float: return math.sqrt(2 * acceleration_m2 * height_m) g = 9.81 # acceleration due to gravity in m/s^2 earth = velocity(acceleration_m2=g) v = earth(height_m=5)() print("The falling velocity is:", v, "m/s") v = earth(height_m=15)() print("The falling velocity is:", v, "m/s") v = earth(height_m=30)() print("The falling velocity is:", v, "m/s") def main() -> None: """ The main function that runs the program. """ test_curring() test_add() test_f_string() test_velocity() if __name__ == "__main__": main() ``` [View Less]

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The exact operation of -m is unclear
by Soni L. May 18, 2023

May 18, 2023

A simple virtual package could be: # foo.py __path__ = [__file__ + ".d"] But unfortunately this doesn't work with -m: # foo.py.d/__main__.py print("this will never run") (n.b. -m foo.__main__ works but nobody's writing that.) Is it possible to change this backwards-compatibly? If not, is it possible to document it slightly better? Thanks.

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Mark a set of keys of a TypedDict as incompatible
by Sync In May 17, 2023

May 17, 2023

I have a couple of {{{TypedDict}}}s for use in type hinting that are supposed to have some sets of incompatible keys. For example, if I need to specify that a particular {{{dict}}} can have {{{bar}}} or {{{baz}}} but not both of them, I can write two {{{TypedDict}}}s: {{{#!highlight python from typing import TypedDict class Foo1(TypedDict): bar: str class Foo2(TypedDict): baz: int Foo = Foo1 | Foo2 foo_instance_1: Foo = { # Works fine 'bar': 'foobar' } foo_instance_2: Foo = { #… [View More]

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Thoughts on allowing Path objects in shlex.join
by mitchell.negus.57＠gmail.com May 13, 2023

May 13, 2023

At the moment, `shlex.join` raises ``` TypeError: expected string or bytes-like object ``` when given `pathlib.Path` objects. Since `subprocess.run` and related subprocess commands allow `Path` since Python 3.6 and 3.8 for Windows, it seems intuitive to me that `shlex.join` be able to handle paths as well. This has been briefly discussed before on the bug tracker (issue 89293, link below), but with the caveat that it was the wrong venue, and should be brought up on this list instead. That … [View More]

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Make ellipsis an indicator of missing implementation
by haael May 3, 2023

May 3, 2023

In examples in the web very often we see unfinished or partial code, where the ellipsis "..." is used in place of missing instructions. Idea: make ellipsis used in that context throw an exception, reminding the user that this code is work in progress. The exception could be called ToDoError, or WorkInProgressError, or simply EllipsisError, and could be derived from NotImplementedError. ``` def my_fun(): ... # todo my_fun() > WorkInProgressError: Implementation of `my_fun` is … [View More]

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Allowing `str.format` to format one or more parameters instead of all parameters
by Samuel Muldoon April 29, 2023

April 29, 2023

Consider the following string: x = r"\mathjax{{color}}{{text}}" string `x` contains two parameters named `color` and the other named `text`. Currently, python requires that the string class method `str.format` contain key-word arguments for *all *parameters, not just *one* parameter result = r"\mathjax{{color}}{{text}}".format(color = "blue" , text = "Spanish") result = "\mathjax{blue}{Spanish}" Can we change str.format so that it is possible to change only one string parameter, but leave … [View More]

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Auto dedent -c arguments.
by Jonathan Crall April 29, 2023

April 29, 2023

I have what I think is a fairly low impact quality of life improvement to suggest for the python CLI. When I'm not working in Python I tend to be working in bash. But often I want to break out and do something quick in Python. I find the `python -c ` CLI very useful for this. For one liners it's perfect. E.g. NEW_VAR=$(python -c "import pathlib; print(pathlib.Path('$MYVAR').parent.parent)") And even if I want to do something multi-line it's pretty easy NEW_VAR=$(python -c " import pathlib … [View More]

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