“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

In my case, the error message was implying that I was working in a headless console. So plt.show() could not work. What worked was calling plt.savefig:

import matplotlib.pyplot as plt

plt.plot([1,2,3], [5,7,4])
plt.savefig("mygraph.png")

I found the answer on a github repository.