通过 scikit-build
使用#
scikit-build
为 Python 扩展模块的用户提供了两个不同的概念。
setuptools
替换(旧版行为)一系列
cmake
模块,其中包含有助于构建 Python 扩展的定义
注意
可以将 scikit-build
的 cmake
模块与 绕过 cmake 设置机制 完全结合,并编写调用 f2py -c
的目标。此用法不推荐,因为这些构建系统文档的重点是脱离内部 numpy.distutils
方法。
对于不需要或不希望 setuptools
替换的情况(即不需要 wheels
),建议改为使用 通过 cmake 使用 中所述的香草 cmake
设置。
斐波那契演练(F77)#
我们将考虑 三种封装方式 - 使用入门 部分中的 fib
示例。
C FILE: FIB1.F
SUBROUTINE FIB(A,N)
C
C CALCULATE FIRST N FIBONACCI NUMBERS
C
INTEGER N
REAL*8 A(N)
DO I=1,N
IF (I.EQ.1) THEN
A(I) = 0.0D0
ELSEIF (I.EQ.2) THEN
A(I) = 1.0D0
ELSE
A(I) = A(I-1) + A(I-2)
ENDIF
ENDDO
END
C END FILE FIB1.F
CMake
仅限模块#
考虑使用以下 CMakeLists.txt
。
### setup project ###
cmake_minimum_required(VERSION 3.9)
project(fibby
VERSION 1.0
DESCRIPTION "FIB module"
LANGUAGES C Fortran
)
# Safety net
if(PROJECT_SOURCE_DIR STREQUAL PROJECT_BINARY_DIR)
message(
FATAL_ERROR
"In-source builds not allowed. Please make a new directory (called a build directory) and run CMake from there.\n"
)
endif()
# Ensure scikit-build modules
if (NOT SKBUILD)
find_package(PythonInterp 3.8 REQUIRED)
# Kanged --> https://github.com/Kitware/torch_liberator/blob/master/CMakeLists.txt
# If skbuild is not the driver; include its utilities in CMAKE_MODULE_PATH
execute_process(
COMMAND "${PYTHON_EXECUTABLE}"
-c "import os, skbuild; print(os.path.dirname(skbuild.__file__))"
OUTPUT_VARIABLE SKBLD_DIR
OUTPUT_STRIP_TRAILING_WHITESPACE
)
list(APPEND CMAKE_MODULE_PATH "${SKBLD_DIR}/resources/cmake")
message(STATUS "Looking in ${SKBLD_DIR}/resources/cmake for CMake modules")
endif()
# scikit-build style includes
find_package(PythonExtensions REQUIRED) # for ${PYTHON_EXTENSION_MODULE_SUFFIX}
# Grab the variables from a local Python installation
# NumPy headers
execute_process(
COMMAND "${PYTHON_EXECUTABLE}"
-c "import numpy; print(numpy.get_include())"
OUTPUT_VARIABLE NumPy_INCLUDE_DIRS
OUTPUT_STRIP_TRAILING_WHITESPACE
)
# F2PY headers
execute_process(
COMMAND "${PYTHON_EXECUTABLE}"
-c "import numpy.f2py; print(numpy.f2py.get_include())"
OUTPUT_VARIABLE F2PY_INCLUDE_DIR
OUTPUT_STRIP_TRAILING_WHITESPACE
)
# Prepping the module
set(f2py_module_name "fibby")
set(fortran_src_file "${CMAKE_SOURCE_DIR}/fib1.f")
set(f2py_module_c "${f2py_module_name}module.c")
# Target for enforcing dependencies
add_custom_target(genpyf
DEPENDS "${fortran_src_file}"
)
add_custom_command(
OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/${f2py_module_c}"
COMMAND ${PYTHON_EXECUTABLE} -m "numpy.f2py"
"${fortran_src_file}"
-m "fibby"
--lower # Important
DEPENDS fib1.f # Fortran source
)
add_library(${CMAKE_PROJECT_NAME} MODULE
"${f2py_module_name}module.c"
"${F2PY_INCLUDE_DIR}/fortranobject.c"
"${fortran_src_file}")
target_include_directories(${CMAKE_PROJECT_NAME} PUBLIC
${F2PY_INCLUDE_DIR}
${NumPy_INCLUDE_DIRS}
${PYTHON_INCLUDE_DIRS})
set_target_properties(${CMAKE_PROJECT_NAME} PROPERTIES SUFFIX "${PYTHON_EXTENSION_MODULE_SUFFIX}")
set_target_properties(${CMAKE_PROJECT_NAME} PROPERTIES PREFIX "")
# Linker fixes
if (UNIX)
if (APPLE)
set_target_properties(${CMAKE_PROJECT_NAME} PROPERTIES
LINK_FLAGS '-Wl,-dylib,-undefined,dynamic_lookup')
else()
set_target_properties(${CMAKE_PROJECT_NAME} PROPERTIES
LINK_FLAGS '-Wl,--allow-shlib-undefined')
endif()
endif()
add_dependencies(${CMAKE_PROJECT_NAME} genpyf)
install(TARGETS ${CMAKE_PROJECT_NAME} DESTINATION fibby)
大部分逻辑与 通过 cmake 使用 中的相同,然而这里值得注意的是,适当的模块后缀是通过 sysconfig.get_config_var("SO")
生成的。结果扩展可以在标准工作流中构建和加载。
ls .
# CMakeLists.txt fib1.f
cmake -S . -B build
cmake --build build
cd build
python -c "import numpy as np; import fibby; a = np.zeros(9); fibby.fib(a); print (a)"
# [ 0. 1. 1. 2. 3. 5. 8. 13. 21.]
setuptools
替换#
注意
截至 2021 年 11 月
在此处描述的用于驱动模块 cmake
构建的行为被认为是旧行为,不应依赖于此。
scikit-build
的实用性在于能够推动生成更多扩展模块,特别是常见的用法模式是生成 Python 可分发版本(例如 PyPI)。
scikit-build
的工作流直接支持此类打包要求。考虑用 setup.py
来扩充项目,该项目定义如下
from skbuild import setup
setup(
name="fibby",
version="0.0.1",
description="a minimal example package (fortran version)",
license="MIT",
packages=['fibby'],
python_requires=">=3.7",
)
与相应的 pyproject.toml
一起
[build-system]
requires = ["setuptools>=42", "wheel", "scikit-build", "cmake>=3.9", "numpy>=1.21"]
build-backend = "setuptools.build_meta"
它们可以与 cmake
一起使用 setuptools
构建扩展,同时其他标准 setuptools
输出。通过 setup.py
运行 cmake
主要用于在需要与未使用 cmake
构建的扩展模块集成时。
ls .
# CMakeLists.txt fib1.f pyproject.toml setup.py
python setup.py build_ext --inplace
python -c "import numpy as np; import fibby.fibby; a = np.zeros(9); fibby.fibby.fib(a); print (a)"
# [ 0. 1. 1. 2. 3. 5. 8. 13. 21.]
在这个情况下,我们修改了模块路径,因为 --inplace
将扩展模块放置在子文件夹中。