“UserWarning: Matplotlib is currently using agg, which is a non-GUI backend, so cannot show the figure.” when plotting figure with pyplot on Pycharm

Question

I am trying to plot a simple graph using pyplot, e.g.:

import matplotlib.pyplot as plt
plt.plot([1,2,3],[5,7,4])
plt.show()

but the figure

Answer 1

Just in case if this helps anybody.

Python version: 3.7.7 platform: Ubuntu 18.04.4 LTS

This came with default python version 3.6.9, however I had installed my own 3.7.7 version python on it (installed building it from source)

tkinter was not working even when the help('module') shows tkinter in the list.

The following steps worked for me:

1. sudo apt-get install tk-dev.

rebuild the python: 1. Navigate to your python folder and run the checks:

cd Python-3.7.7
sudo ./configure --enable-optimizations

2. Build using make command: sudo make -j 8 --- here 8 are the number of processors, check yours using nproc command.

3. Installing using:

   sudo make altinstall
   

Don't use sudo make install, it will overwrite default 3.6.9 version, which might be messy later.

4. Check tkinter now

   python3.7 -m tkinter
   

A windows box will pop up, your tkinter is ready now.