Arrow keys no longer work in Python shell after upgrading Mac OS to Sierra

Question

I'm using zsh, iTerm2 (3.0.9), and pyenv (1.0.2) with pyenv global set to 3.5.2.

In the Python shell, the up and down arrow keys used to work, to access the previous commands in the history. But now after upgrading to OSX 10.12, instead it shows control characters. For example up arrow displays:

^[[A

I've tried installing readline as suggested in Seeing escape characters when pressing the arrow keys in python shell but that didn't help. I don't have the PYTHONSTARTUP variable but didn't used to before, and not sure how that interacts with pyenv.

Answer 1

I solved it by installing python from homebrew:

brew unlink python
brew install python

Answer 2

I had the exact same issue and this command worked for me easy_install -a readline.

Full credit here: ipython complaining about readline

Answer 3

This worked for me:

CFLAGS="-I$(brew --prefix readline)/include -I$(brew --prefix openssl)/include -I$(xcrun --show-sdk-path)/usr/include" \
LDFLAGS="-L$(brew --prefix readline)/lib -L$(brew --prefix openssl)/lib" \
PYTHON_CONFIGURE_OPTS=--enable-unicode=ucs2 \
pyenv install -v 2.7.11

Source: https://medium.com/@pimterry/setting-up-pyenv-on-os-x-with-homebrew-56c7541fd331#.urbdkrc9l

Answer 4

This can happen with upgrading XCode or XCode tools (which often occurs with an OS upgrade) when using brew installed python.

In this case, you just need to reinstall:

brew reinstall python

If you need python 2, remember brew defaults to python3 now, so you need:

brew reinstall python2