[Python-Dev] Where is PyMarshal_ReadShortFromFile() ? (original) (raw)

Tim Peters tim.one@home.com
Fri, 12 Oct 2001 23:56:58 -0400

[James C. Ahlstrom]

Yes they should be public, because PyMarshalReadLongFromFile() is used in import.c to read the Python byte code signature MAGIC from a *.pyc file. I need a PyMarshalReadShortFromFile() to read zip archives in import.c.

There's a finer distinction to be drawn: "public" doesn't mean "C extern", it means a conscious decision that if the API in question ever changes, we promise to bump the Python API version number and so force extension modules to be recompiled (or at least irritate the user with warnings that they should be recompiled). IOW, "public" means "anybody in the world can use this, in or out of the core distribution, and we promise it will never break silently across releases". If you use a C extern function like (say) _PyString_FormatLong outside of the core, and we (say) change the calling sequence, or even get rid of it, tough luck -- we don't promise anything about functions (or macros) whose names begin with an underscore (they're part of "the private C API", C extern or not).

import.c is part of the core, so can use all the private API functions it likes (and we're responsible for making sure it works across releases no matter how wildly the private API functions change).