diff --git a/Doc/using/cmdline.rst b/Doc/using/cmdline.rst index 8e186b3366d5cc31b35584ed6d6ad00ea80b15cf..fc557eebe4ac3e983292b72d9986540245176bf6 100644 --- a/Doc/using/cmdline.rst +++ b/Doc/using/cmdline.rst @@ -411,8 +411,10 @@ Miscellaneous options nested imports). Note that its output may be broken in multi-threaded application. Typical usage is ``python3 -X importtime -c 'import asyncio'``. See also :envvar:`PYTHONPROFILEIMPORTTIME`. - * ``-X dev`` enables the "developer mode": enable debug checks at runtime. - Developer mode: + * ``-X dev``: enable CPython's "developer mode", introducing additional + runtime checks which are too expensive to be enabled by default. It should + not be more verbose than the default if the code is correct: new warnings + are only emitted when an issue is detected. Effect of the developer mode: * Warning filters: add a filter to display all warnings (``"default"`` action), except of :exc:`BytesWarning` which still depends on the @@ -441,8 +443,7 @@ Miscellaneous options The ``-X showalloccount`` option. .. versionadded:: 3.7 - The ``-X importtime``, ``-X dev`` and :envvar:`PYTHONPROFILEIMPORTTIME` - options. + The ``-X importtime`` and ``-X dev`` options. Options you shouldn't use