How to remove frame from matplotlib (pyplot.figure vs matplotlib.figure ) (frameon=False Problematic in matplotlib)

Question

To remove frame in figure, I write

frameon=False

works perfect with pyplot.figure, but with matplotlib.Figure it

Answer 1

plt.box(False)
plt.xticks([])
plt.yticks([])
plt.savefig('fig.png')

should do the trick.