python scrapy No module named 'cryptography.hazmat

在windows下面：

No module named 'cryptography.hazmat.bindings._constant_time'

pip install scrapy

发现了No module named 'cryptography.hazmat.bindings._constant_time'
错误，
解决方法是：
pip install -I cryptography

标签：named,hazmat,constant,cryptography,No,module
来源： https://blog.51cto.com/zhangfang526/2477109