我试图在Windows上安装opencv-python，但是在运行pip install opencv-python命令后，我不断收到以下错误：ERROR: Could not build wheels for opencv-python which use PEP 517 and cannot be installed directly。
我正在使用python版本3.9.0和pip版本pip 20.2.4。
我曾尝试升级我的pip版本以及运行pip install --upgrade pip setuptools wheel，这在类似的线程上可以找到，但是这些似乎都不能解决问题。
运行命令后的完整控制台输出：
Collecting opencv-python
Downloading opencv-python-4.4.0.44.tar.gz (88.9 MB)
|████████████████████████████████| 88.9 MB 3.3 MB/s
Installing build dependencies ... done
Getting requirements to build wheel ... done
Preparing wheel metadata ... done
Collecting numpy>=1.17.3
Downloading numpy-1.19.2.zip (7.3 MB)
|████████████████████████████████| 7.3 MB 6.4 MB/s
Installing build dependencies ... done
Getting requirements to build wheel ... done
Preparing wheel metadata ... done
Building wheels for collected packages: opencv-python, numpy
Building wheel for opencv-python (PEP 517) ... error
ERROR: Command errored out with exit status 1:
command: 'c:\users\david\appdata\local\programs\python\python39\python.exe' 'c:\users\david\appdata\local\programs\python\python39\lib\site-packages\pip\_vendor\pep517\_in_process.py' build_wheel 'C:\Users\David\AppData\Local\Temp\tmpl1finc77'
cwd: C:\Users\David\AppData\Local\Temp\pip-install-gfwb0hqn\opencv-python
Complete output (153 lines):
Not searching for unused variables given on the command line.
CMake Error: CMake was unable to find a build program corresponding to "Ninja". CMAKE_MAKE_PROGRAM is not set. You probably need to select a different build tool.
-- Configuring incomplete, errors occurred!
See also "C:/Users/David/AppData/Local/Temp/pip-install-gfwb0hqn/opencv-python/_cmake_test_compile/build/CMakeFiles/CMakeOutput.log".
Not searching for unused variables given on the command line.
CMake Error at CMakeLists.txt:2 (PROJECT):
Generator
Visual Studio 15 2017 Win64
could not find any instance of Visual Studio.
-- Configuring incomplete, errors occurred!
See also "C:/Users/David/AppData/Local/Temp/pip-install-gfwb0hqn/opencv-python/_cmake_test_compile/build/CMakeFiles/CMakeOutput.log".
Not searching for unused variables given on the command line.
-- The C compiler identification is unknown
CMake Error at CMakeLists.txt:3 (ENABLE_LANGUAGE):
The CMAKE_C_COMPILER:
cl
is not a full path and was not found in the PATH.
To use the NMake generator with Visual C++, cmake must be run from a shell
that can use the compiler cl from the command line. This environment is
unable to invoke the cl compiler. To fix this problem, run cmake from the
Visual Studio Command Prompt (vcvarsall.bat).
Tell CMake where to find the compiler by setting either the environment
variable "CC" or the CMake cache entry CMAKE_C_COMPILER to the full path to
the compiler, or to the compiler name if it is in the PATH.
-- Configuring incomplete, errors occurred!
See also "C:/Users/David/AppData/Local/Temp/pip-install-gfwb0hqn/opencv-python/_cmake_test_compile/build/CMakeFiles/CMakeOutput.log".
See also "C:/Users/David/AppData/Local/Temp/pip-install-gfwb0hqn/opencv-python/_cmake_test_compile/build/CMakeFiles/CMakeError.log".
Not searching for unused variables given on the command line.
-- The C compiler identification is unknown
CMake Error at CMakeLists.txt:3 (ENABLE_LANGUAGE):
The CMAKE_C_COMPILER:
cl
is not a full path and was not found in the PATH.
To use the JOM generator with Visual C++, cmake must be run from a shell
that can use the compiler cl from the command line. This environment is
unable to invoke the cl compiler. To fix this problem, run cmake from the
Visual Studio Command Prompt (vcvarsall.bat).
Tell CMake where to find the compiler by setting either the environment
variable "CC" or the CMake cache entry CMAKE_C_COMPILER to the full path to
the compiler, or to the compiler name if it is in the PATH.
-- Configuring incomplete, errors occurred!
See also "C:/Users/David/AppData/Local/Temp/pip-install-gfwb0hqn/opencv-python/_cmake_test_compile/build/CMakeFiles/CMakeOutput.log".
See also "C:/Users/David/AppData/Local/Temp/pip-install-gfwb0hqn/opencv-python/_cmake_test_compile/build/CMakeFiles/CMakeError.log".
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-- Trying "Ninja (Visual Studio 15 2017 Win64 v141)" generator
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-- Trying "Ninja (Visual Studio 15 2017 Win64 v141)" generator - failure
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-- Trying "Visual Studio 15 2017 Win64 v141" generator
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-- Trying "Visual Studio 15 2017 Win64 v141" generator - failure
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-- Trying "NMake Makefiles (Visual Studio 15 2017 Win64 v141)" generator
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-- Trying "NMake Makefiles (Visual Studio 15 2017 Win64 v141)" generator - failure
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-- Trying "NMake Makefiles JOM (Visual Studio 15 2017 Win64 v141)" generator
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-- Trying "NMake Makefiles JOM (Visual Studio 15 2017 Win64 v141)" generator - failure
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********************************************************************************
scikit-build could not get a working generator for your system. Aborting build.
Building windows wheels for Python 3.9 requires Microsoft Visual Studio 2017.
Get it with "Visual Studio 2017":
https://visualstudio.microsoft.com/vs/
********************************************************************************
----------------------------------------
ERROR: Failed building wheel for opencv-python
Building wheel for numpy (PEP 517) ... done
Created wheel for numpy: filename=numpy-1.19.2-cp39-cp39-win_amd64.whl size=4816060 sha256=18bd09a9c5e107a2e44f8466057d0b423a244fb84949a6d5a6d88534a58e1e4a
Stored in directory: C:\Users\David\AppData\Local\Temp\pip-ephem-wheel-cache-v6mmdzxn\wheels\a3\17\dd\f2dba23a35bb6008732772ccfb13d3d0e537fbc6919ce6862b
Successfully built numpy
Failed to build opencv-python
ERROR: Could not build wheels for opencv-python which use PEP 517 and cannot be installed directly
感谢您提供任何帮助！
答案 0 :(得分：0)
opencv-python还没有预构建的Python 3.9二进制轮子。要从源代码进行编译，必须按照错误指示安装构建工具（Visual Studio 15 2017）：
scikit-build could not get a working generator for your system. Aborting build.
Building windows wheels for Python 3.9 requires Microsoft Visual Studio 2017.
Get it with "Visual Studio 2017":
https://visualstudio.microsoft.com/vs/
opencv-python Python 3.9车轮跟踪问题：https://github.com/skvark/opencv-python/issues/382