无法在windows上安装opencv-python

Question

Ran: pip安装opencv-python

从windows cmd使用admin。第一次设置python时，我不认为它使用了正确的环境变量

获取此错误：

Collecting opencv-python
  Using cached opencv-python-4.4.0.44.tar.gz (88.9 MB)
  Installing build dependencies ... done
  Getting requirements to build wheel ... done
    Preparing wheel metadata ... done
Processing c:\users\shub\appdata\local\pip\cache\wheels\a3\17\dd\f2dba23a35bb6008732772ccfb13d3d0e537fbc6919ce6862b\numpy-1.19.2-cp39-cp39-win_amd64.whl
Building wheels for collected packages: opencv-python
  Building wheel for opencv-python (PEP 517) ... error
  ERROR: Command errored out with exit status 1:
   command: 'c:\users\shub\appdata\local\programs\python\python39\python.exe' 'c:\users\shub\appdata\local\programs\python\python39\lib\site-packages\pip\_vendor\pep517\_in_process.py' build_wheel 'C:\Users\Shub\AppData\Local\Temp\tmpmlx70j_s'
       cwd: C:\Users\Shub\AppData\Local\Temp\pip-install-tdd7o170\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/Shub/AppData/Local/Temp/pip-install-tdd7o170/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/Shub/AppData/Local/Temp/pip-install-tdd7o170/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/Shub/AppData/Local/Temp/pip-install-tdd7o170/opencv-python/_cmake_test_compile/build/CMakeFiles/CMakeOutput.log".
  See also "C:/Users/Shub/AppData/Local/Temp/pip-install-tdd7o170/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/Shub/AppData/Local/Temp/pip-install-tdd7o170/opencv-python/_cmake_test_compile/build/CMakeFiles/CMakeOutput.log".
  See also "C:/Users/Shub/AppData/Local/Temp/pip-install-tdd7o170/opencv-python/_cmake_test_compile/build/CMakeFiles/CMakeError.log".


  ...

  --------------------------------------------------------------------------------
  -- Trying "NMake Makefiles JOM (Visual Studio 15 2017 Win64 v141)" generator
  --------------------------------
  ---------------------------
  ----------------------
  -----------------
  ------------
  -------
  --
  --
  -------
  ------------
  -----------------
  ----------------------
  ---------------------------
  --------------------------------
  -- Trying "NMake Makefiles JOM (Visual Studio 15 2017 Win64 v141)" generator - failure
  --------------------------------------------------------------------------------

  ********************************************************************************
  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
Failed to build opencv-python
ERROR: Could not build wheels for opencv-python which use PEP 517 and cannot be installed directly

C:\Windows\system32>

我安装了visual studio 2019，安装了c++构建工具，以及pip和轮子，但由于某些原因，它无法检测到visual studio。我也在安装后重新启动了我的计算机。不确定如何解决

Answer 1

刚刚遇到了完全相同的问题:D对于我来说，转到visual studio安装程序，在visual studio版本中选择“修改”，然后安装“使用C++进行桌面开发”，然后再次尝试安装它。