·使用pip的时候报错:

　　Fatal error in launcher: Unable to create process using

　　　　解决办法，升级pip    python -m pip install -U pip

·升级pip 时： 输入pip install --upgrade pip　　报错:

　　 ERROR: Could not install packages due to an EnvironmentError: [WinError 5] 拒绝访问。: 'C:......Temp\\pip-uninstall-wl4vp2jt\\pip.exe' Consider using the `--user` option or check the permissions.

　　　　解决: 输入 : install --upgrade --user pip

·pip install coverage :

　　WARNING: Retrying (Retry(total=4, connect=None, read=None, redirect=None, status=None)) after connection broken by 'ConnectTimeoutError(<pip._vendor.urllib3.connection.HTTPSConnection object at 0x00000270D4EAE518>, 'Connection to pypi.org timed out. (connect timeout=15)')': /simple/coverage/

　　　　解决：pip install coverage -i http:///simple --trusted-host