mac更新python超时出错，Read timed out.

WARNING: You are using pip version 20.0.2; however, version 22.2.2 is available.
You should consider upgrading via the '/usr/local/opt/python/bin/python3.7 -m pip install --upgrade pip' command.

按提示输入命令更新：
/usr/local/opt/python/bin/python3.7 -m pip install --upgrade pip

JamSonsMacBook-Pro:~ congjam$ /usr/local/opt/python/bin/python3.7 -m pip install --upgrade pip
Collecting pip
  WARNING: Retrying (Retry(total=4, connect=None, read=None, redirect=None, status=None)) after connection broken by 'ConnectTimeoutError(<pip._vendor.urllib3.connection.VerifiedHTTPSConnection object at 0x10a0e9f60>, 'Connection to files.pythonhosted.org timed out. (connect timeout=15)')': /packages/1f/2c/d9626f045e7b49a6225c6b09257861f24da78f4e5f23af2ddbdf852c99b8/pip-22.2.2-py3-none-any.whl
  Downloading pip-22.2.2-py3-none-any.whl (2.0 MB)
ERROR: Exception:
Traceback (most recent call last):
  File "/usr/local/lib/python3.7/site-packages/pip/_vendor/urllib3/response.py", line 425, in _error_catcher
    yield
  File "/usr/local/lib/python3.7/site-packages/pip/_vendor/urllib3/response.py", line 507, in read
    data = self._fp.read(amt) if not fp_closed else b""
  File "/usr/local/lib/python3.7/site-packages/pip/_vendor/cachecontrol/filewrapper.py", line 62, in read
    data = self.__fp.read(amt)
  File "/usr/local/Cellar/python/3.7.0/Frameworks/Python.framework/Versions/3.7/lib/python3.7/http/client.py", line 447, in read
    n = self.readinto(b)
  File "/usr/local/Cellar/python/3.7.0/Frameworks/Python.framework/Versions/3.7/lib/python3.7/http/client.py", line 491, in readinto
    n = self.fp.readinto(b)
  File "/usr/local/Cellar/python/3.7.0/Frameworks/Python.framework/Versions/3.7/lib/python3.7/socket.py", line 589, in readinto
    return self._sock.recv_into(b)
  File "/usr/local/Cellar/python/3.7.0/Frameworks/Python.framework/Versions/3.7/lib/python3.7/ssl.py", line 1049, in recv_into
    return self.read(nbytes, buffer)
  File "/usr/local/Cellar/python/3.7.0/Frameworks/Python.framework/Versions/3.7/lib/python3.7/ssl.py", line 908, 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 "/usr/local/lib/python3.7/site-packages/pip/_internal/cli/base_command.py", line 186, in _main
    status = self.run(options, args)
  File "/usr/local/lib/python3.7/site-packages/pip/_internal/commands/install.py", line 331, in run
    resolver.resolve(requirement_set)
  File "/usr/local/lib/python3.7/site-packages/pip/_internal/legacy_resolve.py", line 177, in resolve
    discovered_reqs.extend(self._resolve_one(requirement_set, req))
  File "/usr/local/lib/python3.7/site-packages/pip/_internal/legacy_resolve.py", line 333, in _resolve_one
    abstract_dist = self._get_abstract_dist_for(req_to_install)
  File "/usr/local/lib/python3.7/site-packages/pip/_internal/legacy_resolve.py", line 282, in _get_abstract_dist_for
    abstract_dist = self.preparer.prepare_linked_requirement(req)
  File "/usr/local/lib/python3.7/site-packages/pip/_internal/operations/prepare.py", line 482, in prepare_linked_requirement
    hashes=hashes,
  File "/usr/local/lib/python3.7/site-packages/pip/_internal/operations/prepare.py", line 287, in unpack_url
    hashes=hashes,
  File "/usr/local/lib/python3.7/site-packages/pip/_internal/operations/prepare.py", line 159, in unpack_http_url
    link, downloader, temp_dir.path, hashes
  File "/usr/local/lib/python3.7/site-packages/pip/_internal/operations/prepare.py", line 303, in _download_http_url
    for chunk in download.chunks:
  File "/usr/local/lib/python3.7/site-packages/pip/_internal/utils/ui.py", line 160, in iter
    for x in it:
  File "/usr/local/lib/python3.7/site-packages/pip/_internal/network/utils.py", line 39, in response_chunks
    decode_content=False,
  File "/usr/local/lib/python3.7/site-packages/pip/_vendor/urllib3/response.py", line 564, in stream
    data = self.read(amt=amt, decode_content=decode_content)
  File "/usr/local/lib/python3.7/site-packages/pip/_vendor/urllib3/response.py", line 529, in read
    raise IncompleteRead(self._fp_bytes_read, self.length_remaining)
  File "/usr/local/Cellar/python/3.7.0/Frameworks/Python.framework/Versions/3.7/lib/python3.7/contextlib.py", line 130, in __exit__
    self.gen.throw(type, value, traceback)
  File "/usr/local/lib/python3.7/site-packages/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.
WARNING: You are using pip version 20.0.2; however, version 22.2.2 is available.
You should consider upgrading via the '/usr/local/opt/python/bin/python3.7 -m pip install --upgrade pip' command.

解决：带上镜像源
/usr/local/opt/python/bin/python3.7 -m pip install --upgrade pip -i https://pypi.tuna.tsinghua.edu.cn/simple

JamSonsMacBook-Pro:/ congjam$ /usr/local/opt/python/bin/python3.7 -m pip install --upgrade pip -i https://pypi.tuna.tsinghua.edu.cn/simple
Looking in indexes: https://pypi.tuna.tsinghua.edu.cn/simple
Collecting pip
  Downloading https://pypi.tuna.tsinghua.edu.cn/packages/1f/2c/d9626f045e7b49a6225c6b09257861f24da78f4e5f23af2ddbdf852c99b8/pip-22.2.2-py3-none-any.whl (2.0 MB)
     |████████████████████████████████| 2.0 MB 594 kB/s 
Installing collected packages: pip
  Attempting uninstall: pip
    Found existing installation: pip 20.0.2
    Uninstalling pip-20.0.2:
      Successfully uninstalled pip-20.0.2
Successfully installed pip-22.2.2