How to get Python headers for C extensions

When building a Python C extension, you need access to the Python header files. This guide shows how to get the necessary include paths from the Python toolchain.

The recommended way to get the headers is to depend on the @rules_python//python/cc:current_py_cc_headers target. This is a helper target that uses toolchain resolution to find the correct headers for the target platform.

Using the headers

In your BUILD.bazel file, you can add @rules_python//python/cc:current_py_cc_headers to the deps of a cc_library or cc_binary target.

# BUILD.bazel
cc_library(
    name = "my_c_extension",
    srcs = ["my_c_extension.c"],
    deps = ["@rules_python//python/cc:current_py_cc_headers"],
)

This setup ensures that your C extension code can find and use the Python headers during compilation.