Implementation:Tencent Ncnn Setup Py

Knowledge Sources	Tencent_Ncnn
Domains	Build, Python Bindings
Last Updated	2026-02-09 19:00 GMT

Overview

Concrete tool for building and installing the ncnn Python bindings package using a CMake-driven setuptools build system.

Description

This is the Python package build and installation script for the ncnn Python bindings. It implements a CMake-driven setuptools build through three custom classes: find_version() extracts the version from CMakeLists.txt as MAJOR.MINOR.YYYYMMDD, CMakeExtension defines a source-directory-based extension, and CMakeBuild invokes cmake configure and build with flags for NCNN_PYTHON=ON, NCNN_VULKAN=ON, and disabled benchmarks/examples/tools. The build supports MSVC multi-config generators, automatic parallel build based on CPU count, and extensive configuration via environment variables for Vulkan, toolchain, OpenMP, and iOS settings. Package metadata includes Python 3.6-3.14 classifiers, BSD-3 license, and installs from the python/ directory with numpy, tqdm, requests, portalocker, and opencv-python as dependencies.

Usage

Use this script to install ncnn from source via pip install . or to build wheel packages for PyPI distribution. It is the entry point for making ncnn accessible to the Python ecosystem with a standard setuptools interface while handling the complexity of building a C++ CMake project underneath.

Code Reference

Source Location

• Repository: Tencent_Ncnn
• File: setup.py
• Lines: 1-229

Key Classes and Functions

def find_version():
    """Extract version from CMakeLists.txt as MAJOR.MINOR.YYYYMMDD"""

class InstallCommand(install):
    """Custom install command with --vulkan option"""

class CMakeExtension(Extension):
    """Extension using sourcedir instead of file list"""

class CMakeBuild(build_ext):
    """Invokes cmake configure and build for the ncnn native extension"""

Import

from setuptools import setup, find_packages, Extension
from setuptools.command.build_ext import build_ext
from setuptools.command.install import install

I/O Contract

Inputs (Environment Variables)

Name	Type	Required	Description
Vulkan_LIBRARY	str	No	Path to Vulkan library
CMAKE_TOOLCHAIN_FILE	str	No	Path to CMake toolchain file for cross-compilation
PLATFORM	str	No	Target platform (e.g., for iOS builds)
ARCHS	str	No	Target architectures
DEPLOYMENT_TARGET	str	No	Minimum deployment target version
OpenMP_C_FLAGS	str	No	C compiler flags for OpenMP
OpenMP_CXX_FLAGS	str	No	C++ compiler flags for OpenMP
OpenMP_C_LIB_NAMES	str	No	OpenMP C library names
OpenMP_CXX_LIB_NAMES	str	No	OpenMP C++ library names
OpenMP_libomp_LIBRARY	str	No	Path to libomp library
ENABLE_BITCODE	str	No	iOS bitcode setting
ENABLE_ARC	str	No	iOS ARC setting
ENABLE_VISIBILITY	str	No	Symbol visibility setting
EXTRA_CMAKE_ARGS	str	No	Additional CMake arguments (space-separated)
CMAKE_GENERATOR	str	No	CMake generator override (e.g., Ninja, NMake)

Outputs

Name	Type	Description
ncnn Python package	Shared library	Compiled ncnn native extension installed into the Python environment

CMake Configuration

The following CMake flags are set by default during the build:

cmake_args = [
    "-DCMAKE_LIBRARY_OUTPUT_DIRECTORY={}".format(extdir),
    "-DPYTHON_EXECUTABLE={}".format(sys.executable),
    "-DCMAKE_BUILD_TYPE={}".format(cfg),
    "-DNCNN_PYTHON=ON",
    "-DNCNN_VULKAN=ON",
    "-DNCNN_DISABLE_RTTI=OFF",
    "-DNCNN_DISABLE_EXCEPTION=OFF",
    "-DNCNN_BUILD_BENCHMARK=OFF",
    "-DNCNN_BUILD_EXAMPLES=OFF",
    "-DNCNN_BUILD_TOOLS=OFF",
]

Dependencies

Runtime Dependencies

Package	Purpose
numpy	Array operations
tqdm	Progress bars
requests	HTTP client
portalocker	File locking
opencv-python	Image processing

Build Dependencies

Package	Condition
cmake >= 3.12	Installed if cmake is not found on PATH
ninja	Installed on non-Windows if ninja is not found on PATH

Usage Examples

Install from Source

pip install .

Install with Vulkan Support

pip install . --install-option="--vulkan=ON"

Cross-compilation with Toolchain

CMAKE_TOOLCHAIN_FILE=/path/to/toolchain.cmake pip install .

Build with Extra CMake Arguments

EXTRA_CMAKE_ARGS="-DNCNN_VULKAN=OFF" pip install .

Version Scheme

The version is extracted from CMakeLists.txt and formatted as:

{NCNN_VERSION_MAJOR}.{NCNN_VERSION_MINOR}.{YYYYMMDD}

Where YYYYMMDD is the build date, ensuring unique versions for each build.

Related Pages

• Environment:Tencent_Ncnn_Build_Environment