ERPNext Installation CentOS 7.3 error

Install / Update
2

Those guides are dated. So in the wake of for example this that you may have missed:

*SOLVED* Install.py now FAILS on Unbuntu 14.04, Debian 8, Centos 7. What happened? (also same on Ubuntu 16.04) *SOLVED*

This resource here is more current and may serve you better