Python 3.6.1 crashed after I installed readline module

Try pip install gnureadline instead. And remove readline: pip uninstall readline.

As explained by the gnureadline package page on pypi.org:

Some platforms, such as macOS, do not ship with GNU readline installed

This module [bundles] the standard Python readline module with the GNU readline source code, which is compiled and statically linked to it. The end result is a package which is simple to install and requires no extra shared libraries.

So the gnureadline package comes with the required code compiled and linked whereas the builtin python readline library relies on GNU readline (or an alternative) to be installed on the system already.

As far as I can tell, this is the same problem encountered below. I've posted the answer that worked for me, there.

python 3.6 crash after install readline