python——pip安装包升级问题及解决（cmd命令）

Cmd命令更新
pip：python -m pip install --upgrade pip
出现如下报错：

Exception:
Traceback (most recent call last):
  File "C:\Program Files (x86)\Python37-32\lib\site-packages\pip\_vendor\urllib3\response.py", line 360, in _error_catcher
    yield
  File "C:\Program Files (x86)\Python37-32\lib\site-packages\pip\_vendor\urllib3\response.py", line 442, in read
    data = self._fp.read(amt)
  File "C:\Program Files (x86)\Python37-32\lib\site-packages\pip\_vendor\cachecontrol\filewrapper.py", line 62, in read
    data = self.__fp.read(amt)
  File "C:\Program Files (x86)\Python37-32\lib\http\client.py", line 457, in read
    n = self.readinto(b)
  File "C:\Program Files (x86)\Python37-32\lib\http\client.py", line 501, in readinto
    n = self.fp.readinto(b)
  File "C:\Program Files (x86)\Python37-32\lib\socket.py", line 589, in readinto
    return self._sock.recv_into(b)
  File "C:\Program Files (x86)\Python37-32\lib\ssl.py", line 1071, in recv_into
    return self.read(nbytes, buffer)
  File "C:\Program Files (x86)\Python37-32\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:\Program Files (x86)\Python37-32\lib\site-packages\pip\_internal\cli\base_command.py", line 179, in main
    status = self.run(options, args)
  File "C:\Program Files (x86)\Python37-32\lib\site-packages\pip\_internal\commands\install.py", line 315, in run
    resolver.resolve(requirement_set)
  File "C:\Program Files (x86)\Python37-32\lib\site-packages\pip\_internal\resolve.py", line 131, in resolve
    self._resolve_one(requirement_set, req)
  File "C:\Program Files (x86)\Python37-32\lib\site-packages\pip\_internal\resolve.py", line 294, in _resolve_one
    abstract_dist = self._get_abstract_dist_for(req_to_install)
  File "C:\Program Files (x86)\Python37-32\lib\site-packages\pip\_internal\resolve.py", line 242, in _get_abstract_dist_for
    self.require_hashes
  File "C:\Program Files (x86)\Python37-32\lib\site-packages\pip\_internal\operations\prepare.py", line 334, in prepare_linked_requirement
    progress_bar=self.progress_bar
  File "C:\Program Files (x86)\Python37-32\lib\site-packages\pip\_internal\download.py", line 878, in unpack_url
    progress_bar=progress_bar
  File "C:\Program Files (x86)\Python37-32\lib\site-packages\pip\_internal\download.py", line 702, in unpack_http_url
    progress_bar)
  File "C:\Program Files (x86)\Python37-32\lib\site-packages\pip\_internal\download.py", line 946, in _download_http_url
    _download_url(resp, link, content_file, hashes, progress_bar)
  File "C:\Program Files (x86)\Python37-32\lib\site-packages\pip\_internal\download.py", line 639, in _download_url
    hashes.check_against_chunks(downloaded_chunks)
  File "C:\Program Files (x86)\Python37-32\lib\site-packages\pip\_internal\utils\hashes.py", line 62, in check_against_chunks
    for chunk in chunks:
  File "C:\Program Files (x86)\Python37-32\lib\site-packages\pip\_internal\download.py", line 607, in written_chunks
    for chunk in chunks:
  File "C:\Program Files (x86)\Python37-32\lib\site-packages\pip\_internal\utils\ui.py", line 159, in iter
    for x in it:
  File "C:\Program Files (x86)\Python37-32\lib\site-packages\pip\_internal\download.py", line 596, in resp_read
    decode_content=False):
  File "C:\Program Files (x86)\Python37-32\lib\site-packages\pip\_vendor\urllib3\response.py", line 494, in stream
    data = self.read(amt=amt, decode_content=decode_content)
  File "C:\Program Files (x86)\Python37-32\lib\site-packages\pip\_vendor\urllib3\response.py", line 459, in read
    raise IncompleteRead(self._fp_bytes_read, self.length_remaining)
  File "C:\Program Files (x86)\Python37-32\lib\contextlib.py", line 130, in __exit__
    self.gen.throw(type, value, traceback)
  File "C:\Program Files (x86)\Python37-32\lib\site-packages\pip\_vendor\urllib3\response.py", line 365, 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.

解决方法：
1.重连网络，再试几次。
2.这是因为服务器连接超时，使用以下代码

python -m pip install --upgrade pip -i https://pypi.douban.com/simple

若出现以下问题：

Could not install packages due to an EnvironmentError: [WinError 5] 拒绝访问。: 'c:\\program files (x86)\\python37-32\\lib\\site-packages\\pip-19.0.3.dist-info\\entry_points.txt'
Consider using the `--user` option or check the permissions.

最后，我的解决方法是
重新连接网络，下载成功，但是报错如下：

Could not install packages due to an EnvironmentError: [WinError 5] 拒绝访问。: 'c:\\program files (x86)\\python37-32\\lib\\site-packages\\pip-19.0.3.dist-info\\entry_points.txt'
Consider using the `--user` option or check the permissions.

使用

python -m pip install --upgrade pip

最终更新成功至pip 20.0.02

另外，发现原本只用pip就可以打开的命令，更新后需要在前面加上 python -m pip +…来运行了。