为什么使用sudo pip install django 会报错

Exception:
Traceback (most recent call last):
File "/usr/lib/python2.7/dist-packages/pip/basecommand.py", line 209, in main
    status = self.run(options, args)
File "/usr/lib/python2.7/dist-packages/pip/commands/install.py", line 328, in run
    wb.build(autobuilding=True)
File "/usr/lib/python2.7/dist-packages/pip/wheel.py", line 748, in build
    self.requirement_set.prepare_files(self.finder)
File "/usr/lib/python2.7/dist-packages/pip/req/req_set.py", line 360, in prepare_files
    ignore_dependencies=self.ignore_dependencies))
File "/usr/lib/python2.7/dist-packages/pip/req/req_set.py", line 577, in _prepare_file
    session=self.session, hashes=hashes)
File "/usr/lib/python2.7/dist-packages/pip/download.py", line 810, in unpack_url
    hashes=hashes
File "/usr/lib/python2.7/dist-packages/pip/download.py", line 649, in unpack_http_url
    hashes)
File "/usr/lib/python2.7/dist-packages/pip/download.py", line 871, in _download_http_url
    _download_url(resp, link, content_file, hashes)
File "/usr/lib/python2.7/dist-packages/pip/download.py", line 595, in _download_url
    hashes.check_against_chunks(downloaded_chunks)
File "/usr/lib/python2.7/dist-packages/pip/utils/hashes.py", line 46, in check_against_chunks
    for chunk in chunks:
File "/usr/lib/python2.7/dist-packages/pip/download.py", line 563, in written_chunks
    for chunk in chunks:
File "/usr/lib/python2.7/dist-packages/pip/download.py", line 552, in resp_read
    decode_content=False):
File "/usr/share/python-wheels/urllib3-1.13.1-py2.py3-none-any.whl/urllib3/response.py", line 344, in stream
    data = self.read(amt=amt, decode_content=decode_content)
File "/usr/share/python-wheels/urllib3-1.13.1-py2.py3-none-any.whl/urllib3/response.py", line 311, in read
    flush_decoder = True
File "/usr/lib/python2.7/contextlib.py", line 35, in __exit__
    self.gen.throw(type, value, traceback)
File "/usr/share/python-wheels/urllib3-1.13.1-py2.py3-none-any.whl/urllib3/response.py", line 240, in _error_catcher
    raise ReadTimeoutError(self._pool, None, 'Read timed out.')
ReadTimeoutError: HTTPSConnectionPool(host='pypi.python.org', port=443): Read timed out.