我正在尝试在ubuntu 18.04 lts上进行安装，但在终端上却收到此错误。
我已经尝试过重新安装pip，openssl和密码。
我想念我吗？
错误：
Traceback (most recent call last):
File "/usr/bin/pip", line 9, in <module>
from pip import main
File "/usr/lib/python2.7/dist-packages/pip/__init__.py", line 22, in <module>
from pip._vendor.requests.packages.urllib3.exceptions import DependencyWarning
File "/usr/lib/python2.7/dist-packages/pip/_vendor/__init__.py", line 64, in <module>
vendored("cachecontrol")
File "/usr/lib/python2.7/dist-packages/pip/_vendor/__init__.py", line 36, in vendored
__import__(modulename, globals(), locals(), level=0)
File "/usr/share/python-wheels/CacheControl-0.11.7-py2.py3-none-any.whl/cachecontrol/__init__.py", line 9, in <module>
File "/usr/share/python-wheels/CacheControl-0.11.7-py2.py3-none-any.whl/cachecontrol/wrapper.py", line 1, in <module>
File "/usr/share/python-wheels/CacheControl-0.11.7-py2.py3-none-any.whl/cachecontrol/adapter.py", line 4, in <module>
File "/usr/share/python-wheels/requests-2.18.4-py2.py3-none-any.whl/requests/__init__.py", line 84, in <module>
File "/usr/share/python-wheels/urllib3-1.22-py2.py3-none-any.whl/urllib3/contrib/pyopenssl.py", line 46, in <module>
File "/usr/local/lib/python2.7/dist-packages/OpenSSL/__init__.py", line 8, in <module>
from OpenSSL import rand, crypto, SSL
File "/usr/local/lib/python2.7/dist-packages/OpenSSL/rand.py", line 12, in <module>
from OpenSSL._util import (
File "/usr/local/lib/python2.7/dist-packages/OpenSSL/_util.py", line 6, in <module>
from cryptography.hazmat.bindings.openssl.binding import Binding
File "/usr/local/lib/python2.7/dist-packages/cryptography/hazmat/bindings/openssl/binding.py", line 157, in <module>
Binding.init_static_locks()
File "/usr/local/lib/python2.7/dist-packages/cryptography/hazmat/bindings/openssl/binding.py", line 138, in init_static_locks
cls._ensure_ffi_initialized()
File "/usr/local/lib/python2.7/dist-packages/cryptography/hazmat/bindings/openssl/binding.py", line 125, in _ensure_ffi_initialized
cls.lib = build_conditional_library(lib, CONDITIONAL_NAMES)
File "/usr/local/lib/python2.7/dist-packages/cryptography/hazmat/bindings/openssl/binding.py", line 85, in build_conditional_library
if not getattr(lib, condition):
AttributeError: cffi library '_openssl' has no function, constant or global variable named 'Cryptography_HAS_PSK'