NumPy C-API

NumPy provides a C-API to enable users to extend the system and get access to the array object for use in other routines. The best way to truly understand the C-API is to read the source code. If you are unfamiliar with (C) source code, however, this can be a daunting experience at first. Be assured that the task becomes easier with practice, and you may be surprised at how simple the C-code can be to understand. Even if you don’t think you can write C-code from scratch, it is much easier to understand and modify already-written source code then create it de novo.

Python extensions are especially straightforward to understand because they all have a very similar structure. Admittedly, NumPy is not a trivial extension to Python, and may take a little more snooping to grasp. This is especially true because of the code-generation techniques, which simplify maintenance of very similar code, but can make the code a little less readable to beginners. Still, with a little persistence, the code can be opened to your understanding. It is my hope, that this guide to the C-API can assist in the process of becoming familiar with the compiled-level work that can be done with NumPy in order to squeeze that last bit of necessary speed out of your code.

• Python Types and C-Structures
  • New Python Types Defined
  • Other C-Structures
• System configuration
  • Data type sizes
  • Platform information
• Data Type API
  • Enumerated Types
  • Defines
  • C-type names
  • Printf Formatting
• Array API
  • Array structure and data access
  • Creating arrays
  • Dealing with types
  • Array flags
  • Array method alternative API
  • Functions
  • Auxiliary Data With Object Semantics
  • Array Iterators
  • Broadcasting (multi-iterators)
  • Neighborhood iterator
  • Array Scalars
  • Data-type descriptors
  • Conversion Utilities
  • Miscellaneous
• Array Iterator API
  • Array Iterator
  • Simple Iteration Example
  • Simple Multi-Iteration Example
  • Iterator Data Types
  • Construction and Destruction
  • Functions For Iteration
  • Converting from Previous NumPy Iterators
• UFunc API
  • Constants
  • Macros
  • Functions
  • Generic functions
  • Importing the API
• Generalized Universal Function API
  • Definitions
  • Details of Signature
  • C-API for implementing Elementary Functions
• NumPy core libraries
  • NumPy core math library
• C API Deprecations
  • Background
  • Deprecation Mechanism NPY_NO_DEPRECATED_API