If you need to write C extension for Python then this is the place for you.
The full documentation is on Read the Docs.
Code examples and documentation source are right here on GitHub.
I have presented some of this, well mostly the chapter "PyObjects and Reference Counting", at Python conferences so if you prefer videos they are here:
- Introduction
- A Simple Example
- PyObjects and Reference Counting
- Exception Raising
- A Pythonic Coding Pattern for C Functions
- Parsing Python Arguments
- Creating New Types
- Setting and Getting Module Globals
- Logging
- File Paths and Files
- Subclassing and Using super()
- Capsules
- Iterators and Generators
- Pickling C Extension Types
- Setting Compiler Flags
- Debugging
- Memory Leaks
- Thread Safety
- Source Code Layout
- Using C++ With CPython Code
- Miscellaneous
- Further Reading