下载第三方库失败：例如

C:\Users\HP>pip install selenium

Collecting selenium

Downloading https://files.pythonhosted.org/packages/80/d6/4294f0b4bce4de0abf13e17190289f9d0613b0a44e5dd6a7f5ca98459853/selenium-3.141.0-py2.py3-none-any.whl (904kB)

ERROR: Exception:

Traceback (most recent call last):

File "D:\condaq\lib\site-packages\pip\_vendor\urllib3\response.py", line 360, in _error_catcher

yield

File "D:\condaq\lib\site-packages\pip\_vendor\urllib3\response.py", line 442, in read

data = self._fp.read(amt)

File "D:\condaq\lib\site-packages\pip\_vendor\cachecontrol\filewrapper.py", line 62, in read

data = self.__fp.read(amt)

File "D:\condaq\lib\http\client.py", line 447, in read

n = self.readinto(b)

File "D:\condaq\lib\http\client.py", line 491, in readinto

n = self.fp.readinto(b)

File "D:\condaq\lib\socket.py", line 589, in readinto

return self._sock.recv_into(b)

File "D:\condaq\lib\ssl.py", line 1052, in recv_into

return self.read(nbytes, buffer)

File "D:\condaq\lib\ssl.py", line 911, 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 "D:\condaq\lib\site-packages\pip\_internal\cli\base_command.py", line 178, in main

status = self.run(options, args)

File "D:\condaq\lib\site-packages\pip\_internal\commands\install.py", line 352, in run

resolver.resolve(requirement_set)

File "D:\condaq\lib\site-packages\pip\_internal\resolve.py", line 131, in resolve

self._resolve_one(requirement_set, req)

File "D:\condaq\lib\site-packages\pip\_internal\resolve.py", line 294, in _resolve_one

abstract_dist = self._get_abstract_dist_for(req_to_install)

File "D:\condaq\lib\site-packages\pip\_internal\resolve.py", line 242, in _get_abstract_dist_for

self.require_hashes

File "D:\condaq\lib\site-packages\pip\_internal\operations\prepare.py", line 347, in prepare_linked_requirement

progress_bar=self.progress_bar

File "D:\condaq\lib\site-packages\pip\_internal\download.py", line 886, in unpack_url

progress_bar=progress_bar

File "D:\condaq\lib\site-packages\pip\_internal\download.py", line 746, in unpack_http_url

progress_bar)

File "D:\condaq\lib\site-packages\pip\_internal\download.py", line 954, in _download_http_url

_download_url(resp, link, content_file, hashes, progress_bar)

File "D:\condaq\lib\site-packages\pip\_internal\download.py", line 683, in _download_url

hashes.check_against_chunks(downloaded_chunks)

File "D:\condaq\lib\site-packages\pip\_internal\utils\hashes.py", line 62, in check_against_chunks

for chunk in chunks:

File "D:\condaq\lib\site-packages\pip\_internal\download.py", line 651, in written_chunks

for chunk in chunks:

File "D:\condaq\lib\site-packages\pip\_internal\utils\ui.py", line 156, in iter

for x in it:

File "D:\condaq\lib\site-packages\pip\_internal\download.py", line 640, in resp_read

decode_content=False):

File "D:\condaq\lib\site-packages\pip\_vendor\urllib3\response.py", line 494, in stream

data = self.read(amt=amt, decode_content=decode_content)

File "D:\condaq\lib\site-packages\pip\_vendor\urllib3\response.py", line 459, in read

raise IncompleteRead(self._fp_bytes_read, self.length_remaining)

File "D:\condaq\lib\contextlib.py", line 130, in __exit__

self.gen.throw(type, value, traceback)

File "D:\condaq\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.

原因分析

在下载python库的时候，由于国内网络原因，python包的下载速度非常慢，查看pip 文档，只要在 pip的时候控制超时即可, 具体参数为 --default-timeout=100， 后面的时间可以自己指定。

解决措施：

加个参数就好。

pip install --default-timeout=100