错误代码：
Exception: Traceback (most recent call last): File "/usr/lib/python3/dist-packages/pip/req/req_install.py", line 1006, in check_if_exists self.satisfied_by = pkg_resources.get_distribution(str(no_marker)) File "/usr/share/python-wheels/pkg_resources-0.0.0-py2.py3-none-any.whl/pkg_resources/__init__.py", line 535, in get_distribution dist = get_provider(dist) File "/usr/share/python-wheels/pkg_resources-0.0.0-py2.py3-none-any.whl/pkg_resources/__init__.py", line 415, in get_provider return working_set.find(moduleOrReq) or require(str(moduleOrReq))[0] File "/usr/share/python-wheels/pkg_resources-0.0.0-py2.py3-none-any.whl/pkg_resources/__init__.py", line 695, in find raise VersionConflict(dist, req) pkg_resources.VersionConflict: (cryptography 1.2.3 (/usr/lib/python3/dist-packages), Requirement.parse('cryptography>=1.3')) During handling of the above exception, another exception occurred: Traceback (most recent call last): File "/usr/lib/python3/dist-packages/pip/basecommand.py", line 209, in main status = self.run(options, args) File "/usr/lib/python3/dist-packages/pip/commands/install.py", line 317, in run requirement_set.prepare_files(finder) File "/usr/lib/python3/dist-packages/pip/req/req_set.py", line 360, in prepare_files ignore_dependencies=self.ignore_dependencies)) File "/usr/lib/python3/dist-packages/pip/req/req_set.py", line 448, in _prepare_file req_to_install, finder) File "/usr/lib/python3/dist-packages/pip/req/req_set.py", line 387, in _check_skip_installed req_to_install.check_if_exists() File "/usr/lib/python3/dist-packages/pip/req/req_install.py", line 1011, in check_if_exists self.req.project_name AttributeError: 'Requirement' object has no attribute 'project_name'
解决方法：安装全所需库文件即可：
sudo apt-get install build-essential sudo apt-get install python3-dev sudo apt-get install libxml2-de; sudo apt-get install libxslt1-dev sudo apt-get install libssl-dev apt-get install -y libffi-dev pip3 install Twisted pip3 install w3lib pip3 install lxm