[liugedragon]

python_format() rejects valid translations such as %e → %E and %f → %e. The placeholder parser recognizes both scientific conversions, but the float compatibility group only contains f/F/g/G.

Include e/E in that group, matching Python's floating-point percent conversions. Integer, hexadecimal and string conversion groups remain unchanged.

Tests cover all six float conversions in positional and named messages, non-float rejection controls, and a plural catalog. Each positive case also formats the same actual float with both strings. Before the fix, 37 of the 85 new cases fail; after it, all pass.

Validation on Windows / Python 3.13.4 after importing the repository's CLDR 49 data:

• Full suite: 8,292 passed, 10 skipped, 2 xfailed.
• tests/messages: 555 passed.
• Ruff check on both changed files, using the pinned 0.14.10 version: passed.

[chrikrah]

@liugedragon %e and %E join the float group, nothing else moves. Fine to merge from my side.

# git archive a3c5b31 (base a18709c), Python 3.12, CLDR imported, babel.__file__ from the export
$ python -m pytest -q tests
6922 passed, 1219 skipped, 1 xfailed
# python_format(None, Message("v %.2e", "w %.3f")) at a18709c
TranslationError: incompatible format for placeholder 1: 'e' and 'f' are not compatible
# t.po: one python-format entry, msgid "v %.2e", msgstr "w %.3f"
$ msgfmt --version | head -1
msgfmt (GNU gettext-tools) 1.0
$ msgfmt --check-format -o /dev/null t.po; echo exit=$?
exit=0

GNU msgfmt already accepts %e against %f.