python 贝塞尔曲线 bezier curve

import numpy as np
import matplotlib.pyplot as plt
b_xs = []
b_ys = []

def tri_bezier(p1,p2,p3,p4,t):
    parm_1 = (1-t)**3
    parm_2 = 3*(1-t)**2 * t
    parm_3 = 3 * t**2 * (1-t)
    parm_4 = t**3
    px = p1[0] * parm_1 + p2[0] * parm_2 + p3[0] * parm_3 + p4[0] * parm_4
    py = p1[1] * parm_1 + p2[1] * parm_2 + p3[1] * parm_3 + p4[1] * parm_4
    
    return (px,py)

def func():
    t=np.linspace(0,1,10000)   
    for each in t:
        (x,y)=tri_bezier([1.0,0],[2.1,1.1],[3.0,2.1],[4.0,1.0],each)
        b_xs.append(x)
        b_ys.append(y)


func()
plt.figure
plt.plot(b_xs,b_ys)
plt.grid()
plt.show()