saving only one line of a figure as an image (python matplotlib)

[nitrochloric]

hello i have been trying to find a way to save a single line of my plot to save them one-by-one separately in the docs but i wasn't able to find anything of the sort is it possible to do that with something that resembles this? :

import numpy as np
import matplotlib.pyplot as plt

fig = plt.figure()
ax = fig .add_subplot(111)
line1 = ax.plot(x1,y1)
line2 = ax.plot(x2,y2)
fig.savefig(ax(line1),"img.png")

or similar
thanks in advance