pip._vendor.urllib3.exceptions.ReadTimeoutError: HTTPSConnectionPool(host='files.pythonhosted.org',

C:\Users\Roget\PycharmProjects\untitled>pip install numpy==1.16.4
Collecting numpy==1.16.4
  Downloading https://files.pythonhosted.org/packages/ce/61/be72eee50f042db3acf0b1fb86650ad36d6c0d9be9fc29f8505d3b9d6baa/numpy-1.16.4-cp37-cp37m-win_amd64.whl (11.9MB)
     |                                | 40kB 4.9kB/s eta 0:40:36ERROR: Exception:
Traceback (most recent call last):
  File "c:\users\roget\appdata\local\programs\python\python37\lib\site-packages\pip-19.3-py3.7.egg\pip\_vendor\urllib3\response.py", line 425, in _error_catcher
    yield
  File "c:\users\roget\appdata\local\programs\python\python37\lib\site-packages\pip-19.3-py3.7.egg\pip\_vendor\urllib3\response.py", line 507, in read
    data = self._fp.read(amt) if not fp_closed else b""
  File "c:\users\roget\appdata\local\programs\python\python37\lib\site-packages\pip-19.3-py3.7.egg\pip\_vendor\cachecontrol\filewrapper.py", line 62, in read
    data = self.__fp.read(amt)
  File "c:\users\roget\appdata\local\programs\python\python37\lib\http\client.py", line 457, in read
    n = self.readinto(b)
  File "c:\users\roget\appdata\local\programs\python\python37\lib\http\client.py", line 501, in readinto
    n = self.fp.readinto(b)
  File "c:\users\roget\appdata\local\programs\python\python37\lib\socket.py", line 589, in readinto
    return self._sock.recv_into(b)
  File "c:\users\roget\appdata\local\programs\python\python37\lib\ssl.py", line 1071, in recv_into
    return self.read(nbytes, buffer)
  File "c:\users\roget\appdata\local\programs\python\python37\lib\ssl.py", line 929, in read
    return self._sslobj.read(len, buffer)
socket.timeout: The read operation timed out

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "c:\users\roget\appdata\local\programs\python\python37\lib\site-packages\pip-19.3-py3.7.egg\pip\_internal\cli\base_command.py", line 153, in _main
    status = self.run(options, args)
  File "c:\users\roget\appdata\local\programs\python\python37\lib\site-packages\pip-19.3-py3.7.egg\pip\_internal\commands\install.py", line 381, in run
    resolver.resolve(requirement_set)
  File "c:\users\roget\appdata\local\programs\python\python37\lib\site-packages\pip-19.3-py3.7.egg\pip\_internal\legacy_resolve.py", line 201, in resolve
    self._resolve_one(requirement_set, req)
  File "c:\users\roget\appdata\local\programs\python\python37\lib\site-packages\pip-19.3-py3.7.egg\pip\_internal\legacy_resolve.py", line 365, in _resolve_one
    abstract_dist = self._get_abstract_dist_for(req_to_install)
  File "c:\users\roget\appdata\local\programs\python\python37\lib\site-packages\pip-19.3-py3.7.egg\pip\_internal\legacy_resolve.py", line 313, in _get_abstract_dist_for
    req, self.session, self.finder, self.require_hashes
  File "c:\users\roget\appdata\local\programs\python\python37\lib\site-packages\pip-19.3-py3.7.egg\pip\_internal\operations\prepare.py", line 194, in prepare_linked_requireme
nt
    progress_bar=self.progress_bar
  File "c:\users\roget\appdata\local\programs\python\python37\lib\site-packages\pip-19.3-py3.7.egg\pip\_internal\download.py", line 465, in unpack_url
    progress_bar=progress_bar
  File "c:\users\roget\appdata\local\programs\python\python37\lib\site-packages\pip-19.3-py3.7.egg\pip\_internal\download.py", line 316, in unpack_http_url
    progress_bar)
  File "c:\users\roget\appdata\local\programs\python\python37\lib\site-packages\pip-19.3-py3.7.egg\pip\_internal\download.py", line 551, in _download_http_url
    _download_url(resp, link, content_file, hashes, progress_bar)
  File "c:\users\roget\appdata\local\programs\python\python37\lib\site-packages\pip-19.3-py3.7.egg\pip\_internal\download.py", line 253, in _download_url
    hashes.check_against_chunks(downloaded_chunks)
  File "c:\users\roget\appdata\local\programs\python\python37\lib\site-packages\pip-19.3-py3.7.egg\pip\_internal\utils\hashes.py", line 80, in check_against_chunks
    for chunk in chunks:
  File "c:\users\roget\appdata\local\programs\python\python37\lib\site-packages\pip-19.3-py3.7.egg\pip\_internal\download.py", line 223, in written_chunks
    for chunk in chunks:
  File "c:\users\roget\appdata\local\programs\python\python37\lib\site-packages\pip-19.3-py3.7.egg\pip\_internal\utils\ui.py", line 160, in iter
    for x in it:
  File "c:\users\roget\appdata\local\programs\python\python37\lib\site-packages\pip-19.3-py3.7.egg\pip\_internal\download.py", line 212, in resp_read
    decode_content=False):
  File "c:\users\roget\appdata\local\programs\python\python37\lib\site-packages\pip-19.3-py3.7.egg\pip\_vendor\urllib3\response.py", line 564, in stream
    data = self.read(amt=amt, decode_content=decode_content)
  File "c:\users\roget\appdata\local\programs\python\python37\lib\site-packages\pip-19.3-py3.7.egg\pip\_vendor\urllib3\response.py", line 529, in read
    raise IncompleteRead(self._fp_bytes_read, self.length_remaining)
  File "c:\users\roget\appdata\local\programs\python\python37\lib\contextlib.py", line 130, in __exit__
    self.gen.throw(type, value, traceback)
  File "c:\users\roget\appdata\local\programs\python\python37\lib\site-packages\pip-19.3-py3.7.egg\pip\_vendor\urllib3\response.py", line 430, in _error_catcher
    raise ReadTimeoutError(self._pool, None, "Read timed out.")
pip._vendor.urllib3.exceptions.ReadTimeoutError: HTTPSConnectionPool(host='files.pythonhosted.org', port=443): Read timed out.

原因分析： 网络不行，切换一个网络进行下载numpy

结果显示：