Is it safe to reinstall Python 2.7.10 on El Capitan Mac OS X? I reinstalled my Python 2.7.10, and updated to Python 2.7.11 I reinstalled with command 'brew reinstall python' Thank you
No, you can't safely update the system-provided Python. Too many moving parts of the operating system and 3rd-party software relies on what the OS provides rather than what you want to use.
You can install Python via brew safely however, as it doesn't replace the system Python. Brew asks you to update your PATH variable, and in your terminal with an updated PATH you'll automatically use the brew-provided Python. This leaves the system Python in-place to be used by everything else.