blank plot with matplotlib inside pipenv on Mac OS X

Question

Short version

Trying to show a plot via plt.show() inside a pipenv opens a window that is completely white, no errors. Resizing the window makes it completely black. Expecting to see a plot depicting a function f(x) = x^2 (see code below).

More info

Saving a plot with plt.savefig('tmp.png') works fine.

Installing matplotlib to the system wide python3 via $ pip3 install matplotlib causes no issues. The issue only arises when matplotlib is installed within a pipenv executing the same code (see below).

Versions:

• Mac OS Mojave 10.14.2
• pipenv version 2018.11.26
• matplotlib==3.0.2
• pipenv and system python version 3.7.2

Somewhat surprisingly, I can get it to work on an older Mac running Sierra 10.12.6 with otherwise same versions of pipenv, python, and matplotlib. But I don't think I ever ran into the same issue on that one.

What I have tried

1. installed tcl-tk: $ brew install tcl-tk
2. set backend: $ echo "backend: TkAgg" >> ~/.matplotlib/matplotlibrc
3. installed X11 server

What am I missing?

At this point I am out of ideas. Any hints as to how to get a plot to show up properly within a pipenv is greatly appreciated.

Does this have anything to do with a framework install of python as mentioned in the matplotlib docs?

Code

import numpy as np
import matplotlib
from matplotlib import pyplot as plt

if __name__ == "__main__":
    plt.figure()
    x = np.arange(0, 10, 1)
    y = x*x

    plt.plot(x, y)
    # plt.savefig("tmp.png")    # works fine
    plt.show()

Answer 1

If you're still having this problem, I fixed it by installing python as a framework (I installed conda brew cask install anaconda. Then add your Anaconda to path: export PATH=$HOME/anaconda3/bin/:$PATH via vim ~/.bash_profile. I can still engage pipenv with Anaconda.