问无法使用pip安装PyQt5

EN

pip install PyQt5

sudo -H pip install PyQt5

ERROR: Could not find a version that satisfies the requirement PyQt5 (from versions: none)
ERROR: No matching distribution found for PyQt5

pip3 install PyQt5

Traceback (most recent call last):
  File "/usr/local/bin/pip3", line 5, in <module>
    from pkg_resources import load_entry_point
  File "/usr/local/lib/python2.7/dist-packages/pkg_resources/__init__.py", line 3241, in <module>
    @_call_aside
  File "/usr/local/lib/python2.7/dist-packages/pkg_resources/__init__.py", line 3225, in _call_aside
    f(*args, **kwargs)
  File "/usr/local/lib/python2.7/dist-packages/pkg_resources/__init__.py", line 3254, in _initialize_master_working_set
    working_set = WorkingSet._build_master()
  File "/usr/local/lib/python2.7/dist-packages/pkg_resources/__init__.py", line 585, in _build_master
    return cls._build_from_requirements(__requires__)
  File "/usr/local/lib/python2.7/dist-packages/pkg_resources/__init__.py", line 598, in _build_from_requirements
    dists = ws.resolve(reqs, Environment())
  File "/usr/local/lib/python2.7/dist-packages/pkg_resources/__init__.py", line 786, in resolve
    raise DistributionNotFound(req, requirers)
pkg_resources.DistributionNotFound: The 'pip==9.0.1' distribution was not found and is required by the application