我们在安装一些包的时候，比如TensorFlow等等，如果直接使用:
pip install tensorflow这句命令来进行安装的时候，我们会发现此时安装的速度不仅非常慢，而且还有可能出现网络超时的情况，比如如下问题：
Traceback (most recent call last):File "/home/pengzhang/anaconda3/envs/MyTensorflow/lib/python3.9/site-packages/pip/_internal/cli/base_command.py", line 180, in exc_logging_wrapperstatus = run_func(*args)File "/home/pengzhang/anaconda3/envs/MyTensorflow/lib/python3.9/site-packages/pip/_internal/cli/req_command.py", line 245, in wrapperreturn func(self, options, args)File "/home/pengzhang/anaconda3/envs/MyTensorflow/lib/python3.9/site-packages/pip/_internal/commands/install.py", line 377, in runrequirement_set = resolver.resolve(File "/home/pengzhang/anaconda3/envs/MyTensorflow/lib/python3.9/site-packages/pip/_internal/resolution/resolvelib/resolver.py", line 179, in resolveself.factory.preparer.prepare_linked_requirements_more(reqs)File "/home/pengzhang/anaconda3/envs/MyTensorflow/lib/python3.9/site-packages/pip/_internal/operations/prepare.py", line 552, in prepare_linked_requirements_moreself._complete_partial_requirements(File "/home/pengzhang/anaconda3/envs/MyTensorflow/lib/python3.9/site-packages/pip/_internal/operations/prepare.py", line 467, in _complete_partial_requirementsfor link, (filepath, _) in batch_download:File "/home/pengzhang/anaconda3/envs/MyTensorflow/lib/python3.9/site-packages/pip/_internal/network/download.py", line 183, in __call__for chunk in chunks:File "/home/pengzhang/anaconda3/envs/MyTensorflow/lib/python3.9/site-packages/pip/_internal/cli/progress_bars.py", line 53, in _rich_progress_barfor chunk in iterable:File "/home/pengzhang/anaconda3/envs/MyTensorflow/lib/python3.9/site-packages/pip/_internal/network/utils.py", line 63, in response_chunksfor chunk in response.raw.stream(File "/home/pengzhang/anaconda3/envs/MyTensorflow/lib/python3.9/site-packages/pip/_vendor/urllib3/response.py", line 622, in streamdata = self.read(amt=amt, decode_content=decode_content)File "/home/pengzhang/anaconda3/envs/MyTensorflow/lib/python3.9/site-packages/pip/_vendor/urllib3/response.py", line 587, in readraise IncompleteRead(self._fp_bytes_read, self.length_remaining)File "/home/pengzhang/anaconda3/envs/MyTensorflow/lib/python3.9/contextlib.py", line 137, in __exit__self.gen.throw(typ, value, traceback)File "/home/pengzhang/anaconda3/envs/MyTensorflow/lib/python3.9/site-packages/pip/_vendor/urllib3/response.py", line 443, in _error_catcherraise ReadTimeoutError(self._pool, None, "Read timed out.")
pip._vendor.urllib3.exceptions.ReadTimeoutError: HTTPSConnectionPool(host='files.pythonhosted.org', port=443): Read timed out.这主要是因为直接使用pip进行安装的时候需要从外网下载相关的软件包，很容易出现网络超时的情况，这个时候我们可以使用一些国内的镜像源：
清华源： https://pypi.tuna.tsinghua.edu.cn/simple/阿里云： http://mirrors.aliyun.com/pypi/simple/中国科技大学： https://pypi.mirrors.ustc.edu.cn/simple/豆瓣(douban)：http://pypi.douban.com/simple/清华大学： https://pypi.tuna.tsinghua.edu.cn/simple/中国科学技术大学： http://pypi.mirrors.ustc.edu.cn/simple/比如这里选择清华源进行安装：
pip install tensorflow -i https://pypi.tuna.tsinghua.edu.cn/simple/我们就会发现安装速度快了许多。
