Fix pure Python implementation of `fromisoformat()` to reject spaces
in fractional part of time specifications.  This matches the behavior
of the C implementation in CPython, and prevents the method from parsing
them incorrectly.

This fixes Django's test suite by enabling a fallback to their own
(working) parser.

Backports: python/cpython#130962

…isoformat()` (python#130962)

Fix the pure Python implementation of `fromisoformat()` to reject any
non-digit characters, including whitespace, in the fractional part
of time specification.  This makes the behavior consistent with the C
implementation, and prevents incorrect parsing of these fractions
(e.g. `.400 ` would be misinterpreted as `.04`).

Co-authored-by: Peter Bierma <[email protected]>
Co-authored-by: Paul Ganssle <[email protected]>
(cherry picked from commit 33494b4)

…misoformat()` (#130962) (#131076)

gh-130959: Reject whitespace in fractions, in pure Python `fromisoformat()` (#130962)

Fix the pure Python implementation of `fromisoformat()` to reject any
non-digit characters, including whitespace, in the fractional part
of time specification.  This makes the behavior consistent with the C
implementation, and prevents incorrect parsing of these fractions
(e.g. `.400 ` would be misinterpreted as `.04`).

Co-authored-by: Peter Bierma <[email protected]>
Co-authored-by: Paul Ganssle <[email protected]>
(cherry picked from commit 33494b4)

Co-authored-by: Michał Górny <[email protected]>

…n `fromisoformat()` (pythonGH-130962) (pythonGH-131076)

pythongh-130959: Reject whitespace in fractions, in pure Python `fromisoformat()` (pythonGH-130962)

Fix the pure Python implementation of `fromisoformat()` to reject any
non-digit characters, including whitespace, in the fractional part
of time specification.  This makes the behavior consistent with the C
implementation, and prevents incorrect parsing of these fractions
(e.g. `.400 ` would be misinterpreted as `.04`).

Co-authored-by: Peter Bierma <[email protected]>
Co-authored-by: Paul Ganssle <[email protected]>
(cherry picked from commit 33494b4)
(cherry picked from commit 27fd328)

Co-authored-by: Victor Stinner <[email protected]>
Co-authored-by: Michał Górny <[email protected]>

…mat()` (GH-130962) (GH-131076) (#131086)

Fix the pure Python implementation of `fromisoformat()` to reject any
non-digit characters, including whitespace, in the fractional part
of time specification.  This makes the behavior consistent with the C
implementation, and prevents incorrect parsing of these fractions
(e.g. `.400 ` would be misinterpreted as `.04`).

(cherry picked from commit 33494b4)
(cherry picked from commit 27fd328)

Co-authored-by: Victor Stinner <[email protected]>
Co-authored-by: Michał Górny <[email protected]>

…isoformat()` (python#130962)

* pythongh-130959: Reject whitespace in fractions, in pure Python `fromisoformat()`

Fix the pure Python implementation of `fromisoformat()` to reject any
non-digit characters, including whitespace, in the fractional part
of time specification.  This makes the behavior consistent with the C
implementation, and prevents incorrect parsing of these fractions
(e.g. `.400 ` would be misinterpreted as `.04`).

* Add the news entry

* Use a different example to fix Sphinx lint

* Apply suggestions from code review

Co-authored-by: Peter Bierma <[email protected]>
Co-authored-by: Paul Ganssle <[email protected]>

* Try fixing `:func:` ref.

---------

Co-authored-by: Peter Bierma <[email protected]>
Co-authored-by: Paul Ganssle <[email protected]>