| # CPython source code | |
| This section gives an overview of CPython's code structure and provides | |
| a summary of file locations for modules and built-ins. | |
| ## Source code layout | |
| For a Python module, the typical layout is: | |
| * `Lib/<module>.py` | |
| * `Modules/_<module>.c` (if there's also a C accelerator module) | |
| * `Lib/test/test_<module>.py` | |
| * `Doc/library/<module>.rst` | |
| For an extension module, the typical layout is: | |
| * `Modules/<module>module.c` | |
| * `Lib/test/test_<module>.py` | |
| * `Doc/library/<module>.rst` | |
| For builtin types, the typical layout is: | |
| * `Objects/<builtin>object.c` | |
| * `Lib/test/test_<builtin>.py` | |
| * [`Doc/builtins/stdtypes.rst`](../Doc/builtins/stdtypes.rst) | |
| For builtin functions, the typical layout is: | |
| * [`Python/bltinmodule.c`](../Python/bltinmodule.c) | |
| * [`Lib/test/test_builtin.py`](../Lib/test/test_builtin.py) | |
| * [`Doc/builtins/functions.rst`](../Doc/builtins/functions.rst) | |
| Some exceptions to these layouts are: | |
| * built-in type `int` is at [`Objects/longobject.c`](../Objects/longobject.c) | |
| * built-in type `str` is at [`Objects/unicodeobject.c`](../Objects/unicodeobject.c) | |
| * built-in module `sys` is at [`Python/sysmodule.c`](../Python/sysmodule.c) | |
| * built-in module `marshal` is at [`Python/marshal.c`](../Python/marshal.c) | |
| * Windows-only module `winreg` is at [`PC/winreg.c`](../PC/winreg.c) |