Matplotlib axvline() and axhline() functions in Matplotlib

# -*- encoding: utf-8 -*-
# @File  : axhline.py    
# @Author: Mr. Luo
# @Date: 2021/11/6 13:40
'''
feature: Draw parallel to x Horizontal reference line of axis 
'''
import matplotlib.pyplot as plt
import numpy as np
'''
y： The starting point of the horizontal reference line 
c： Reference line color 
ls: Reference line style 
lw: Reference line width 
 Translational ： The function function above , Call signature and parameter description can also be translated to function axvline() On 
'''
x = np.linspace(0.2, 10, 1000)
y = np.sin(x)
plt.plot(x, y, ls="-.", c='b', label="figure")
plt.legend()
plt.axhline(y=0.0, c="g", ls="--", lw=2)
plt.axvline(x=4.0, c="r", ls="--", lw=2)
 
plt.show()