return type same as class gives NameError.
I have the following small module: =-=-=-=-=-=-=-=-=-=-=-= 8< =-=-=-=-=-=-=-=-=-=-=-=-= from typing import NamedTuple, TypeAlias, Union from collections.abc import Sequence PNT: TypeAlias = tuple[float, float] class Pnt (NamedTuple): x: float y: float def __add__(self, other: PNT) -> Pnt: return Pnt(self[0] + other[0], self[1] + other[1]) =-=-=-=-=-=-=-=-=-=-=-= >8 =-=-=-=-=-=-=-=-=-=-=-=-= But when I import this, I get the following diagnostic: Traceback (most recent call last): File "", line 1, in File "/home/sisc/projecten/iudex/problem.py", line 10, in class Pnt (NamedTuple): File "/home/sisc/projecten/iudex/problem.py", line 14, in Pnt def __add__(self, other: PNT) -> Pnt: ^^^ NameError: name 'Pnt' is not defined. Did you mean: 'PNT'? Can someone explain what I am doing wrong? -- https://mail.python.org/mailman/listinfo/python-list
making your own DirEntry.
I am writing a program that goes through file hierarchies and I am mostly
using scandir for that which produces DirEntry instances.
At times it would be usefull if I could make my own DirEntry for a specific
path, however when I try, I get the following diagnostic:
os.DirEntry('snap')
Traceback (most recent call last):
File "", line 1, in
TypeError: cannot create 'posix.DirEntry' instances
Does anyone have an idea for why this limitation and how to go around it.
At this moment I don't consider pathlib very usefull, it lacks the
follow_symlinks parameter in the is_dir, is_file, ... methods.
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Re: making your own DirEntry.
Op 22/12/2023 om 21:39 schreef DL Neil via Python-list:
Antoon,
On 12/23/23 01:00, Antoon Pardon via Python-list wrote:
I am writing a program that goes through file hierarchies and I am
mostly
using scandir for that which produces DirEntry instances.
At times it would be usefull if I could make my own DirEntry for a
specific
path, however when I try, I get the following diagnostic:
os.DirEntry('snap')
Traceback (most recent call last):
File "", line 1, in
TypeError: cannot create 'posix.DirEntry' instances
Does anyone have an idea for why this limitation and how to go around
it.
At this moment I don't consider pathlib very usefull, it lacks the
follow_symlinks parameter in the is_dir, is_file, ... methods.
Can't recall ever trying this.
The manual (https://docs.python.org/3/library/os.html#os.DirEntry)
suggests that a DirEntry is one of those Python data-constructs which
it creates, but we may only use: "cannot create".
Secondly, that a DirEntry object consists of a lot more than the
directory-name, eg its path.
Thirdly, that os.scandir() deals (only) with concrete directories -
unlike pathlib's ability to work with both the real thing and abstract
files/dirs.
Why create a DirEntry? Why not go directly to os.mkdir() or whatever?
Because I have functions with DirEntry parameters.
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Re: making your own DirEntry.
Op 23/12/2023 om 12:34 schreef Barry Scott: On 23 Dec 2023, at 09:48, Antoon Pardon via Python-list wrote: Because I have functions with DirEntry parameters. I would duck-type a class I control to be my DirEnrry in this situation. Would also help you when debugging as you can tell injected DirEntry from "real" DirEntry. Yes that seems to be, the way to go. -- Antoon Pardon -- https://mail.python.org/mailman/listinfo/python-list
Re: mypy question
Op 29/12/2023 om 16:02 schreef Karsten Hilbert via Python-list: Am Fri, Dec 29, 2023 at 07:49:17AM -0700 schrieb Mats Wichmann via Python-list: I am not sure why mypy thinks this gmPG2.py:554: error: Argument "queries" to "run_rw_queries" has incompatible type "List[Dict[str, str]]"; expected "List[Dict[str, Union[str, List[Any], Dict[str, Any" [arg-type] rows, idx = run_rw_queries(link_obj = conn, queries = queries, return_data = True) ^~~ should be flagged. The intent is for "queries" to be a list of dicts with keys of str and values of str OR list of anything OR dict with keys of str and values of anything I'd have thunk list[dict[str,str]] matches that ? Dict[str, str] means the key type and value type should both be strings, Indeed, I know that much, list[dict[str, str]] is what is getting passed in in this particular invocation of run_rw_queries(). For what it's worth here's the signature of that function: def run_rw_queries ( link_obj:_TLnkObj=None, queries:list[dict[str, str | list | dict[str, Any]]]=None, end_tx:bool=False, return_data:bool=None, get_col_idx:bool=False, verbose:bool=False ) -> tuple[list[dbapi.extras.DictRow], dict[str, int] | None]: Given that I would have thought that passing in list[dict[str, str]] for "queries" ought to be type safe. Mypy indicates otherwise which I am not grokking as to why. but in your retelling above you indicate lots of possible value types... actually the mypy guess seems to be a pretty good recreation of your psuedo-code description. I agree that mypy's grasp of my intent from queries:list[dict[str, str | list | dict[str, Any]]]=None, into "List[Dict[str, Union[str, List[Any], Dict[str, Any" seems accurate. I just don't understand why list[dict[str, str]] should not pass that construct. Sorry for the late reaction and may be I am missing something, but I was wondering if your type hint for queries shouldn't be the following. queries:list[dict[str,str]|dict[str,list]|dict[str,dict[str, dict[str, Ant]]] My impression at this moment is that you are write something like: dict[str, str | int] as as shorthand for dict[str, str] | dict[str, int]. But those two are different types. -- Antoon Pardon. -- https://mail.python.org/mailman/listinfo/python-list
Re: Extract lines from file, add to new files
Op 14/01/2024 om 13:28 schreef Left Right via Python-list: Python isn't a context-free language, so the grammar that is used to describe it doesn't actually describe the language... so, it's a "pretend grammar" that ignores indentation. No it doesn't. Here is the definition of a block, it clearly mentions indentation: block: | NEWLINE INDENTstatements DEDENT | simple_stmts But you are correct that python in not a context-free language. But so is any programming language. Yet a lot of those non context-free language designers thought it helpful to have a modified/extended BNF description of a superset of the intended language and used other means to further check whether the code in question was valid or not. -- Antoon Pardon -- https://mail.python.org/mailman/listinfo/python-list
Re: A missing iterator on itertools module?
Op 28/03/2024 om 17:45 schreef ast via Python-list:
Hello
Suppose I have these 3 strings:
s1 = "AZERTY"
s2 = "QSDFGH"
s3 = "WXCVBN"
and I need an itertor who delivers
A Q W Z S C E D C ...
I didn't found anything in itertools to do the job.
The documentation mentions a roundrobin recipe.
So I came up with this solution:
list(chain.from_iterable(zip("AZERTY", "QSDFGH", "WXCVBN")))
['A', 'Q', 'W', 'Z', 'S', 'X', 'E', 'D', 'C', 'R', 'F', 'V', 'T', 'G',
'B', 'Y', 'H', 'N']
But if your strings are not equal, this will only produce a partial result.
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Re: Beazley's Problem
Op 23/09/2024 om 09:44 schreef Annada Behera via Python-list: The "next-level math trick" Newton-Raphson has nothing to do with functional programming. I have written solvers in purely iterative style. What is your point. Any problem solved in a functional style can also be solved in a pure interative style. So you having written something in an interative style doesn't contradict Newton-Raphson being expressable in a functional style. As far as I know, Newton-Raphson is the opposite of functional programming as you iteratively solve for the root. Functional programming is stateless where you are not allowed to store any state (current best guess root). That doesn't prevent you from passing state along as a parameter, usualy in some helper function. -- Antoon Pardon. -- https://mail.python.org/mailman/listinfo/python-list
