Mailman 3 January 2020 - Python-ideas

addition of "nameof" operator
by Johan Vergeer Feb. 4, 2020

Feb. 4, 2020

I have worked with both C# and Python for a while now and there is one feature of C# I'm missing in the Python language. This feature is the "nameof" operator. (https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/operators…). The place I use this the most in C# is in `ToString()` methods or logging messages. This makes sure the developer cannot forget to update the name of a member. As an example I created this `Person` class. ``` class Person: def __init__(self, name, age):… [View More]

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concurrent.futures cancel pending at Executor.shutdown
by Miguel Ángel Prosper Feb. 3, 2020

Feb. 3, 2020

Hi, I think it would be very helpful to have an additional argument (cancel for example) added to Executor.shutdown that cancels all pending futures submitted to the executor. Then context manager would gain the ability to abort all futures incase of a exception, additionally this would also implement the missing cuterpart of the multiprocessing module terminate, currently we only have close.

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Re: addition of "nameof" operator
by Alex Hall Feb. 2, 2020

Feb. 2, 2020

Here's a simple runtime implementation that doesn't require any dependencies or source code access: import dis import inspect from functools import lru_cache def nameof(_): frame = inspect.currentframe().f_back return _nameof(frame.f_code, frame.f_lasti) @lru_cache def _nameof(code, offset): instructions = list(dis.get_instructions(code)) (current_instruction_index, current_instruction), = ( (index, instruction) for index, instruction in enumerate(… [View More]

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Proposal for an additional type system
by guenter-hofer＠aon.at Jan. 31, 2020

Jan. 31, 2020

The types in most programming languages are only technical types. If a variable has a type, you may know that it is of type integer or double, but you don't know if it's a length or an area. The types required are semantic types. stypes: length area time speed scalar allowed expressions: length = length length + length : length time = time time + time : time scalar * length : length scalar * time : time sqrt(area) : length speed = speed length / time : speed … [View More]

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Allow spaces between string prefix and the string literal
by Mikhail V Jan. 30, 2020

Jan. 30, 2020

I would like to see possibility to put spaces between the string prefix and the string literal so I could write e.g. like this: print (f "x: {x}") IMO it would help with legibility especially noticable with by proportional fonts. Mikhail

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"and if" and "or if" for trailing if statements - including explicit fallthrough
by Soni L. Jan. 28, 2020

Jan. 28, 2020

I'd like to see the ability to do: if x: 1 and if y: 2 or if z: 3 The truth table for these would be: x | y | z | result 0 | _ | 0 | (none) 0 | _ | 1 | 3 1 | 0 | _ | 1,3 1 | 1 | _ | 1,2,3 and each statement is evaluated once, when encountered. (as such, y and z may not be evaluated at all, if their evaluation is not necessary to determine the outcome.) This enables the usage of fallthrough - "or if" is a fallthrough case, and the "or" in it is because its body … [View More]

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Improve SyntaxError for obvious issue:
by Σταύρος Ντέντος Jan. 28, 2020

Jan. 28, 2020

Hello there, If I have simply missed a double colon starting a for loop File "./bbq.py", line 160 for config_file in config_files ^ SyntaxError: invalid syntax the message is not as straightforward. I am not sure what the status quo of these messages are, but: could it be enhanced? Ντέντος Σταύρος

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Is the deployment standard for WSGI ready?
by Jesús Gómez Jan. 28, 2020

Jan. 28, 2020

In the PEP-3333[1] they say the following: """ After a sufficient number of servers and frameworks have implemented WSGI to provide field experience with varying deployment requirements, it may make sense to create another PEP, describing a deployment standard for WSGI servers and application frameworks. """ Did this happen already? Will this happen anytime? [1] https://www.python.org/dev/peps/pep-3333/

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Relative path for pyvenv.cfg:home
by Jeff Edwards Jan. 27, 2020

Jan. 27, 2020

Hi all! This is my first time proposing or submitting an idea, so I apologize if I've gone about all of this the wrong way. I've been using venv for lots of development but came upon a use-case where I wanted to extend the capabilities of it to support a home directory relative to the pyvenv.cfg file. This can be quite useful for tools intending to be used as an executable (e.g. black, supervisor), but need to be packaged with an application that may or may not use the same interpreter. In … [View More]

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Suggestion for language addition
by Jan Bakuwel Jan. 23, 2020

Jan. 23, 2020

Hi folks, I have a few decades of experience with software engineering using assembler, C, FORTRAN, Pascal, Ada and a fair number of other languages. I've been using Python as well for a number of years now. Both Pascal and Ada have "end" statements, which make the code (at least for me :-) ) a lot more readable and maintainable, especially if the code within if/while/for statements gets longer and nested deeper. These statements exist in these languages for a good reason. I had a look … [View More]in the archives to see if someone else already proposed this but couldn't find anything, so here goes. Please let me know whether you think this idea is worth to convert to a PEP. thanks, Jan Idea: To include optional "end if", "end while", "end for" and "end <function name>", "end <class name>" in the language. The Python interpreter would test that any "end" matches with the correct corresponding statements and have the correct indentation, in other words throw an error if you would write "end if" where an "end while" should be. This will be a great help preventing errors with procedural logic, that I now have to painstakingly debug at runtime, especially after moving bits of code around. Python editors would ideally highlight "if" and "end if" just like they now highlight "if". By default different colors could be picked for "if" and "end if", "while" and "end while" etc. All this is completely optional of course, so it won't break any existing code. Advantages: - better readability and maintainability - help prevent procedural logic mistakes - editors could use this for improved highlighting of code Disadvantages: - none :-) it's optional, just like the typing that was introduced in Python 3 Code example: def func (i: int, j: int, k: int) -> None: if (i == 3): while (i < 15): i += 1 if (k == 8): lots of other code (think a page or more) lots of other code here is more code <- to which if or while does this belong? and a bit more further code The code could be rewritten like this: def func (i: int, j: int, k: int) -> None: if (i == 3): while (i < 15): i += 1 if (k == 8): lots of other code (think a page or more) lots of other code end if end while (writing "end if" would throw an error at parse time) here is more code and a bit more end if end func further code Looking forward to your feedback! regards, Jan NEW ZEALAND [View Less]

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