pip install Appium-Python-Client 报Failed to build cryptography错误解决办法

使用Pthon编写自动化脚本时，导入appium失败，百度查到需要安装Appium-Python-Client，于是CMD执行pip install Appium-Python-Client， 报错：

Building wheels for collected packages: cryptography
Building wheel for cryptography (PEP 517) … error

ERROR: Failed cleaning build dir for cryptography
Failed to build cryptography
ERROR: Could not build wheels for cryptography which use PEP 517 and cannot be installed directly

 解决办法：

1.执行命令：easy_install -U pip

展示如下图则表示pip升级成功

 2.执行命令：pip install cryptography

 展示如下图则表示安装成功

 3.执行命令：pip install Appium-Python-Client

 展示图下图则表示安装成功