read time out problems is generally due to the python-coated wall resulting in slower download speeds, pip download timeout.
Solution one:
Add --default-timeout: Custom timeout time, usually able to solve most of the problems timeout, but can not improve download speeds.
pip -default-timeout=1000 -U networkx
Solution two:
Changing python package download the source, the use of domestic mirroring package: Tsinghua resources.
In Windows:
New \ Users \ Administrator \ under pip folder, create pip.ini file, copy the code below into it, save: C.
[global]
index-url = https://pypi.tuna.tsinghua.edu.cn/simple