C:\Windows\system32>pip install virtualenv
Collecting virtualenv
Using cached virtualenv-20.2.2-py2.py3-none-any.whl (5.7 MB)
Requirement already satisfied: filelock<4,>=3.0.0 in c:\users\pc\appdata\local\packages\pythonsoftwarefoundation.python.3.8_qbz5n2kfra8p0\localcache\local-packages\python38\site-packages (from virtualenv) (3.0.12)
Requirement already satisfied: appdirs<2,>=1.4.3 in c:\users\pc\appdata\local\packages\pythonsoftwarefoundation.python.3.8_qbz5n2kfra8p0\localcache\local-packages\python38\site-packages (from virtualenv) (1.4.4)
Requirement already satisfied: six<2,>=1.9.0 in c:\users\pc\appdata\local\packages\pythonsoftwarefoundation.python.3.8_qbz5n2kfra8p0\localcache\local-packages\python38\site-packages (from virtualenv) (1.15.0)
Requirement already satisfied: distlib<1,>=0.3.1 in c:\users\pc\appdata\local\packages\pythonsoftwarefoundation.python.3.8_qbz5n2kfra8p0\localcache\local-packages\python38\site-packages (from virtualenv) (0.3.1)
Installing collected packages: virtualenv
WARNING: The script virtualenv.exe is installed in ‘C:\Users\pc\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.8_qbz5n2kfra8p0\LocalCache\local-packages\Python38\Scripts’ which is not on PATH.
Consider adding this directory to PATH or, if you prefer to suppress this warning, use --no-warn-script-location.
ERROR: After October 2020 you may experience errors when installing or updating packages. This is because pip will change the way that it resolves dependency conflicts.

We recommend you use --use-feature=2020-resolver to test your packages with the new resolver before it becomes the default.

pipenv 2020.11.15 requires virtualenv-clone>=0.2.5, which is not installed.
Successfully installed virtualenv-20.2.2
WARNING: You are using pip version 20.2.1; however, version 20.3.3 is available.
You should consider upgrading via the ‘C:\Users\pc\AppData\Local\Microsoft\WindowsApps\PythonSoftwareFoundation.Python.3.8_qbz5n2kfra8p0\python.exe -m pip install --upgrade pip’ command.

C:\Windows\system32>virtualen ff
’virtualen’ 不是内部或外部命令，也不是可运行的程序
或批处理文件。