pip install 报错?报错

执行 pip install requests 时，报错：

root@iZ23totlue9Z:~/mine/zz-python# pip install requests
Exception:
Traceback (most recent call last):
  File "/usr/local/lib/python2.7/dist-packages/pip/basecommand.py", line 246, in main
    status = self.run(options, args)
  File "/usr/local/lib/python2.7/dist-packages/pip/commands/install.py", line 342, in run
    requirement_set.prepare_files(finder)
  File "/usr/local/lib/python2.7/dist-packages/pip/req/req_set.py", line 345, in prepare_files
    functools.partial(self._prepare_file, finder))
  File "/usr/local/lib/python2.7/dist-packages/pip/req/req_set.py", line 290, in _walk_req_to_install
    more_reqs = handler(req_to_install)
  File "/usr/local/lib/python2.7/dist-packages/pip/req/req_set.py", line 415, in _prepare_file
    req_to_install, finder)
  File "/usr/local/lib/python2.7/dist-packages/pip/req/req_set.py", line 366, in _check_skip_installed
    req_to_install.check_if_exists()
  File "/usr/local/lib/python2.7/dist-packages/pip/req/req_install.py", line 986, in check_if_exists
    self.satisfied_by = pkg_resources.get_distribution(self.req)
  File "/usr/local/lib/python2.7/dist-packages/pip/_vendor/pkg_resources/__init__.py", line 533, in get_distribution
    dist = get_provider(dist)
  File "/usr/local/lib/python2.7/dist-packages/pip/_vendor/pkg_resources/__init__.py", line 413, in get_provider
    return working_set.find(moduleOrReq) or require(str(moduleOrReq))[0]
  File "/usr/local/lib/python2.7/dist-packages/pip/_vendor/pkg_resources/__init__.py", line 934, in require
    needed = self.resolve(parse_requirements(requirements))
  File "/usr/local/lib/python2.7/dist-packages/pip/_vendor/pkg_resources/__init__.py", line 811, in resolve
    env = Environment(self.entries)
  File "/usr/local/lib/python2.7/dist-packages/pip/_vendor/pkg_resources/__init__.py", line 991, in __init__
    self.scan(search_path)
  File "/usr/local/lib/python2.7/dist-packages/pip/_vendor/pkg_resources/__init__.py", line 1021, in scan
    self.add(dist)
  File "/usr/local/lib/python2.7/dist-packages/pip/_vendor/pkg_resources/__init__.py", line 1037, in add
    if self.can_add(dist) and dist.has_version():
  File "/usr/local/lib/python2.7/dist-packages/pip/_vendor/pkg_resources/__init__.py", line 2742, in has_version
    self.version
  File "/usr/local/lib/python2.7/dist-packages/pip/_vendor/pkg_resources/__init__.py", line 2550, in version
    for line in self._get_metadata(self.PKG_INFO):
  File "/usr/local/lib/python2.7/dist-packages/pip/_vendor/pkg_resources/__init__.py", line 2594, in _get_metadata
    for line in self.get_metadata_lines(name):
  File "/usr/local/lib/python2.7/dist-packages/pip/_vendor/pkg_resources/__init__.py", line 1990, in get_metadata_lines
    return yield_lines(self.get_metadata(name))
  File "/usr/local/lib/python2.7/dist-packages/pip/_vendor/pkg_resources/__init__.py", line 1984, in get_metadata
    with open(self.path,'rU') as f:
IOError: [Errno 2] No such file or directory: '/usr/lib/python2.7/dist-packages/setuptools.egg-info'