configparser: create unnamed section with mapping protocol access

[Rogdham]

Feature or enhancement

Current state (3.14):

Since gh-123077 (CPython 3.14), it is possible to create an unnamed section with configparser:

>>> cfg1 = configparser.ConfigParser(allow_unnamed_section=True)
>>> cfg1.add_section(configparser.UNNAMED_SECTION)
>>> cfg1.set(configparser.UNNAMED_SECTION, "foo", "bar")
>>> cfg1.write(fobj1)

This gives the following output file:

foo = bar

However, the mapping protocol access is not supported:

>>> cfg2 = configparser.ConfigParser(allow_unnamed_section=True)
>>> cfg2[configparser.UNNAMED_SECTION] = {"foo": "bar"}
>>> cfg2.write(fobj2)

Gives the following output file:

[<UNNAMED_SECTION>]
foo = bar

Proposal:

Implement the mapping protocol for access of the unnamed section in configparser.

Has this already been discussed elsewhere?

This is a minor feature, which does not need previous discussion elsewhere

Links to previous discussion of this feature:

No response

Linked PRs

• gh-136282: Configparser: create unnamed sections via mapping protocol access #136313