安装pip的时候总是网络超时
cheng@cheng-PC:~/Desktop$ python get-pip.py
Collecting pip
  Downloading https://files.pythonhosted.org/packages/5f/25/e52d3f31441505a5f3af41213346e5b6c221c9e086a166f3703d2ddaf940/pip-18.0-py2.py3-none-any.whl (1.3MB)
    72% |███████████████████████         | 942kB 6.0kB/s eta 0:01:02Exception:
Traceback (most recent call last):
  File "/tmp/tmpGRFFJJ/pip.zip/pip/_internal/basecommand.py", line 141, in main
    status = self.run(options, args)
  File "/tmp/tmpGRFFJJ/pip.zip/pip/_internal/commands/install.py", line 299, in run
    resolver.resolve(requirement_set)
  File "/tmp/tmpGRFFJJ/pip.zip/pip/_internal/resolve.py", line 102, in resolve
    self._resolve_one(requirement_set, req)
  File "/tmp/tmpGRFFJJ/pip.zip/pip/_internal/resolve.py", line 256, in _resolve_one
    abstract_dist = self._get_abstract_dist_for(req_to_install)
  File "/tmp/tmpGRFFJJ/pip.zip/pip/_internal/resolve.py", line 209, in _get_abstract_dist_for
    self.require_hashes
  File "/tmp/tmpGRFFJJ/pip.zip/pip/_internal/operations/prepare.py", line 283, in prepare_linked_requirement
    progress_bar=self.progress_bar
  File "/tmp/tmpGRFFJJ/pip.zip/pip/_internal/download.py", line 836, in unpack_url
    progress_bar=progress_bar
  File "/tmp/tmpGRFFJJ/pip.zip/pip/_internal/download.py", line 673, in unpack_http_url
    progress_bar)
  File "/tmp/tmpGRFFJJ/pip.zip/pip/_internal/download.py", line 897, in _download_http_url
    _download_url(resp, link, content_file, hashes, progress_bar)
  File "/tmp/tmpGRFFJJ/pip.zip/pip/_internal/download.py", line 617, in _download_url
    hashes.check_against_chunks(downloaded_chunks)
  File "/tmp/tmpGRFFJJ/pip.zip/pip/_internal/utils/hashes.py", line 48, in check_against_chunks
    for chunk in chunks:
  File "/tmp/tmpGRFFJJ/pip.zip/pip/_internal/download.py", line 585, in written_chunks
    for chunk in chunks:
  File "/tmp/tmpGRFFJJ/pip.zip/pip/_internal/utils/ui.py", line 159, in iter
    for x in it:
  File "/tmp/tmpGRFFJJ/pip.zip/pip/_internal/download.py", line 574, in resp_read
    decode_content=False):
  File "/tmp/tmpGRFFJJ/pip.zip/pip/_vendor/urllib3/response.py", line 465, in stream
    data = self.read(amt=amt, decode_content=decode_content)
  File "/tmp/tmpGRFFJJ/pip.zip/pip/_vendor/urllib3/response.py", line 430, in read
    raise IncompleteRead(self._fp_bytes_read, self.length_remaining)
  File "/usr/lib/python2.7/contextlib.py", line 35, in __exit__
    self.gen.throw(type, value, traceback)
  File "/tmp/tmpGRFFJJ/pip.zip/pip/_vendor/urllib3/response.py", line 336, in _error_catcher
    raise ReadTimeoutError(self._pool, None, 'Read timed out.')
ReadTimeoutError: HTTPSConnectionPool(host='files.pythonhosted.org', port=443): Read timed out.
cheng@cheng-PC:~/Desktop$ python get-pip.py
Collecting pip
  Downloading https://files.pythonhosted.org/packages/5f/25/e52d3f31441505a5f3af41213346e5b6c221c9e086a166f3703d2ddaf940/pip-18.0-py2.py3-none-any.whl (1.3MB)
    35% |███████████▎                    | 460kB 4.4kB/s eta 0:03:12Exception:
Traceback (most recent call last):
  File "/tmp/tmpEN6GxU/pip.zip/pip/_internal/basecommand.py", line 141, in main
    status = self.run(options, args)
  File "/tmp/tmpEN6GxU/pip.zip/pip/_internal/commands/install.py", line 299, in run
    resolver.resolve(requirement_set)
  File "/tmp/tmpEN6GxU/pip.zip/pip/_internal/resolve.py", line 102, in resolve
    self._resolve_one(requirement_set, req)
  File "/tmp/tmpEN6GxU/pip.zip/pip/_internal/resolve.py", line 256, in _resolve_one
    abstract_dist = self._get_abstract_dist_for(req_to_install)
  File "/tmp/tmpEN6GxU/pip.zip/pip/_internal/resolve.py", line 209, in _get_abstract_dist_for
    self.require_hashes
  File "/tmp/tmpEN6GxU/pip.zip/pip/_internal/operations/prepare.py", line 283, in prepare_linked_requirement
    progress_bar=self.progress_bar
  File "/tmp/tmpEN6GxU/pip.zip/pip/_internal/download.py", line 836, in unpack_url
    progress_bar=progress_bar
  File "/tmp/tmpEN6GxU/pip.zip/pip/_internal/download.py", line 673, in unpack_http_url
    progress_bar)
  File "/tmp/tmpEN6GxU/pip.zip/pip/_internal/download.py", line 897, in _download_http_url
    _download_url(resp, link, content_file, hashes, progress_bar)
  File "/tmp/tmpEN6GxU/pip.zip/pip/_internal/download.py", line 617, in _download_url
    hashes.check_against_chunks(downloaded_chunks)
  File "/tmp/tmpEN6GxU/pip.zip/pip/_internal/utils/hashes.py", line 48, in check_against_chunks
    for chunk in chunks:
  File "/tmp/tmpEN6GxU/pip.zip/pip/_internal/download.py", line 585, in written_chunks
    for chunk in chunks:
  File "/tmp/tmpEN6GxU/pip.zip/pip/_internal/utils/ui.py", line 159, in iter
    for x in it:
  File "/tmp/tmpEN6GxU/pip.zip/pip/_internal/download.py", line 574, in resp_read
    decode_content=False):
  File "/tmp/tmpEN6GxU/pip.zip/pip/_vendor/urllib3/response.py", line 465, in stream
    data = self.read(amt=amt, decode_content=decode_content)
  File "/tmp/tmpEN6GxU/pip.zip/pip/_vendor/urllib3/response.py", line 430, in read
    raise IncompleteRead(self._fp_bytes_read, self.length_remaining)
  File "/usr/lib/python2.7/contextlib.py", line 35, in __exit__
    self.gen.throw(type, value, traceback)
  File "/tmp/tmpEN6GxU/pip.zip/pip/_vendor/urllib3/response.py", line 336, in _error_catcher
    raise ReadTimeoutError(self._pool, None, 'Read timed out.')
ReadTimeoutError: HTTPSConnectionPool(host='files.pythonhosted.org', port=443): Read timed out.