Rationale
=========
argparse performs a complex formatting of the usage for argument grouping
and for line wrapping to fit the terminal width. This formatting has been
a constant source of bugs for at least 10 years (see linked issues below)
where defensive assertion errors are triggered or brackets and paranthesis
are not properly handeled.
Problem
=======
The current implementation of argparse usage formatting relies on regular
expressions to group arguments usage only to separate them again later
with another set of regular expressions. This is a complex and error prone
approach that caused all the issues linked below. Special casing certain
argument formats has not solved the problem. The following are some of
the most common issues:
- empty `metavar`
- mutually exclusive groups with `SUPPRESS`ed arguments
- metavars with whitespace
- metavars with brackets or paranthesis
Solution
========
The following two comments summarize the solution:
- https://github.com/python/cpython/issues/82091#issuecomment-1093832187
- https://github.com/python/cpython/issues/77048#issuecomment-1093776995
Mainly, the solution is to rewrite the usage formatting to avoid the
group-then-separate approach. Instead, the usage parts are kept separate
and only joined together at the end. This allows for a much simpler
implementation that is easier to understand and maintain. It avoids the
regular expressions approach and fixes the corresponding issues.
This closes the following GitHub issues:
- #62090
- #62549
- #77048
- #82091
- #89743
- #96310
- #98666
These PRs become obsolete:
- #15372
- #96311
Add missing import to code that handles too large files and offsets.
Use list, not tuple, for a mutable sequence.
Add tests to prevent similar mistakes.
---------
Co-authored-by: Gregory P. Smith [Google LLC] <greg@krypto.org>
Co-authored-by: Kirill Podoprigora <kirill.bast9@mail.ru>
This change makes sure all extension/builtin modules have their init function run first by the main interpreter before proceeding with import in the original interpreter (main or otherwise). This means when the import of a single-phase init module fails in an isolated subinterpreter, it won't tie any global state/callbacks to the subinterpreter.
Add the ability to enable/disable the GIL at runtime, and use that in
the C module loading code.
We can't know before running a module init function if it supports
free-threading, so the GIL is temporarily enabled before doing so. If
the module declares support for running without the GIL, the GIL is
later disabled. Otherwise, the GIL is permanently enabled, and will
never be disabled again for the life of the current interpreter.
We already intern and immortalize most string constants. In the
free-threaded build, other constants can be a source of reference count
contention because they are shared by all threads running the same code
objects.
Now, such classes will no longer require changes in Python 3.13 in the normal case.
The test suite for robotframework passes with no DeprecationWarnings under this PR.
I also added a new DeprecationWarning for the case where `_field_types` exists
but is incomplete, since that seems likely to indicate a user mistake.
Add _PyType_LookupRef and use incref before setting attribute on type
Makes setting an attribute on a class and signaling type modified atomic
Avoid adding re-entrancy exposing the type cache in an inconsistent state by decrefing after type is updated
This is an experimental feature, for internal use.
Setting tkinter._debug = True before creating the root window enables
printing every executed Tcl command (or a Tcl command equivalent to the
used Tcl C API).
This will help to convert a Tkinter example into Tcl script to check
whether the issue is caused by Tkinter or exists in the underlying Tcl/Tk
library.
* Add PhotoImage.read() to read an image from a file.
* Add PhotoImage.data() to get the image data.
* Add background and grayscale parameters to PhotoImage.write().
* Add the PhotoImage method copy_replace() to copy a region
from one image to other image, possibly with pixel zooming and/or
subsampling.
* Add from_coords parameter to PhotoImage methods copy(), zoom() and subsample().
* Add zoom and subsample parameters to PhotoImage method copy().
Ali Hamdan
John Sirois
Ned Deily
Tian Gao
Eric Snow
Brett Simmers
Sam Gross
James Hilton-Balfe
Barney Gale
Dino Viehland
Jeong, YunWon
Brandt Bucher
Jelle Zijlstra
denballakh
Łukasz Langa
Mark Shannon
Serhiy Storchaka
Erlend E. Aasland
Pablo Galindo Salgado
Thomas Grainger
Petr Viktorin
Kerim Kabirov
Xie Yanbo
Alyssa Coghlan
Lysandros Nikolaou
Pieter Eendebak
Terry Jan Reedy