Clarify sqlite3 documentation of PEP 249 compliance for commit modes #99828
Description
Documentation
The sqlite3 documentation for the new Connection.autocommit attribute introduced in PR #93823 states:
.. attribute:: autocommit
This attribute controls :pep:`249`-compliant transaction behaviour.
:attr:`!autocommit` has three allowed values:
* ``False``: Select :pep:`249`-compliant transaction behaviour,
implying that :mod:`!sqlite3` ensures a transaction is always open.
This is the recommended value of :attr:`!autocommit`.
* ``True``: Use SQLite's `autocommit mode`_.
:meth:`commit` and :meth:`rollback` have no effect in this mode.
* :data:`LEGACY_TRANSACTION_CONTROL`:
Pre-Python 3.12 (non-:pep:`249`-compliant) transaction control.
See :attr:`isolation_level` for more details.
The sentence ‘This attribute controls :pep:249-compliant transaction behaviour.’ is misleading as only the new manual commit mode (autocommit=False) is PEP-249-compliant, since PEP 249 specifies only the manual commit mode.
Likewise, the sentence ‘Pre-Python 3.12 (non-:pep:249-compliant) transaction control.’ is misleading as only the legacy manual commit mode (isolation_level='DEFERRED', isolation_level='EXCLUSIVE', or isolation_level='IMMEDIATE') is non-PEP-249-compliant, since PEP 249 specifies only the manual commit mode.