sphinx-intl update adds python-format flag to messages containing %

[emlys]

Given a POT file with a message that contains a %, sphinx-intl update will produce a PO file where that message has an added #, python-format flag. That flag indicates that the message is a python format string, but all sphinx-intl messages should come from RST.

Example POT file:

# pot_dir/test.pot

msgid ""
msgstr ""

msgid "the % of change in sediment"
msgstr ""

Produces this PO file:

msgid ""
msgstr ""
"Project-Id-Version: PROJECT VERSION\n"
"Report-Msgid-Bugs-To: EMAIL@ADDRESS\n"
"POT-Creation-Date: 2021-12-06 15:01-0800\n"
"PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
"Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
"Language-Team: LANGUAGE <LL@li.org>\n"
"MIME-Version: 1.0\n"
"Content-Type: text/plain; charset=utf-8\n"
"Content-Transfer-Encoding: 8bit\n"
"Generated-By: Babel 2.9.1\n"

#, python-format
msgid "the % of change in sediment"
msgstr ""

[tk0miya]

It seems babel library adds the "python-format" flag when reading the message catalog from a pot file. I'm not sure what is happened inside babel...

$ python
Python 3.7.12 (default, Oct  5 2021, 14:06:57)
[Clang 11.0.3 (clang-1103.0.32.62)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> from babel.messages.pofile import read_po
>>> catalog = read_po(open('test.pot'))
>>> list(catalog)
[<Message '' (flags: [])>, <Message 'the % of change in sediment' (flags: ['python-format'])>]

[emlys]

It looks like this is a longstanding issue with babel: python-babel/babel#35 that might not get solved anytime soon. In the meantime, would it make sense for sphinx-intl to filter out all python-format flags?

[tk0miya]

Thank you for the pointer.

In the meantime, would it make sense for sphinx-intl to filter out all python-format flags?

Sounds good. Could you make a pull request, please? Then, I'll merge it soon.