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 or @rules_python//python/cc:current_py_cc_headers_abi3 targets. These are convenience targets that use 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.

Note

The :current_py_cc_headers target provides all the Python headers. This may include ABI-specific information.

Using the stable ABI headers

If you’re building for the Python stable ABI, then depend on @rules_python//python/cc:current_py_cc_headers_abi3. This target contains only objects relevant to the Python stable ABI. Remember to define Py_LIMITED_API when building such extensions.

# BUILD.bazel
cc_library(
    name = "my_stable_abi_extension",
    srcs = ["my_stable_abi_extension.c"],
    deps = ["@rules_python//python/cc:current_py_cc_headers_abi3"],
)