import numpy as np import matplotlib.pyplot as plt import matplotlib.lines as lines fig = plt.figure() l1 = lines.Line2D([0, 1], [0, 1], transform=fig.transFigure, figure=fig) l2 = lines.Line2D([0, 1], [1, 0], transform=fig.transFigure, figure=fig) fig.lines.extend([l1, l2])