Matplotlib plot not appearing with elpy in Emacs

For solving this, you can use different back-end:

import matplotlib
matplotlib.use('TkAgg')
import matplotlib.pyplot as plt

Other GUI backends:

• TkAgg
• WX
• QTAgg
• QT4Agg

Run your code using: C-u C-c C-c

Fix tmux issue with conda

source
Problem: When running a conda environment and opening tmux on macOS, a utility called path_helper is run again. Essentially, the shell is initialized twice which messes up the ${PATH} so that the wrong Python version shows up within tmux.

Solution  If using bash, edit /etc/profile and add one line. (For zsh, edit /etc/zprofile)