What is the meaning of indexing in plt.plot()-CodePudding

I am learning about matplotlib and found code : plt.plot([])[0]. Can u explain what means of index on that code?

Im trying to make animation using matplotlib and one of the example using that code. I dont understand the meaning of index in that code

CodePudding user response：

lets say you plot multiple lines with plt.plot, e.g. like this

import numpy as np
from matplotlib import pyplot as plt

# evenly sampled time at 200ms intervals
t = np.arange(0., 5., 0.2)

# red dashes, blue squares and green triangles
plt.plot(t, t, 'r--', t, t**2, 'bs', t, t**3, 'g^')
plt.show()

you can use the index after plt.plot() for retrieving each single Line2D object, eg. like this

line1 = plt.plot(t, t, 'r--', t, t**2, 'bs', t, t**3, 'g^')[0]
line2 = plt.plot(t, t, 'r--', t, t**2, 'bs', t, t**3, 'g^')[1]

and then interact with the single Line2D object, for example with

x1, y1, = line1.get_data()

for more methods see https://matplotlib.org/stable/api/_as_gen/matplotlib.lines.Line2D.html