pyasn1 安装异常

初探Scrapy 时，也不知道按照哪里的文档装的，由于安装低版本的pyasn1 后，使用pip uninstall 都 卸不了

步骤如下：

异常：

pyasn1-modules 0.2. has requirement pyasn1<0.5.,>=0.4., but you'll have pyasn1 0.1.7 which is incompatible.

网上方案：

https://blog.csdn.net/ksx_120999/article/details/80012650

pip install pyasn1-modules

报错

Cannot uninstall 'pyasn1'. It is a distutils installed project and thus we cannot accurately determine which files belong to it which would lead to only a partial uninstall.

貌似重新安装是先uninstall 然后，卸不了

于是从 pyasn1 官网下源代码再安装

https://pypi.org/project/pyasn1/#files

官网地址

下载

下载后，解压，进入根目录

python setup.py build
python setup.py install

OK，pyasn1 己安装指定版本。