question : how to plot bending moment diagram in python

from numpy import *
import matplotlib.pyplot as plt
print('all dimensions are in meter (m)/n all loads in kn');
l= 6;
c = 4;
d = 10
f= 8;
ra = 11;
rb = 11;
x1 = arange(0,1,.01)
x2 = arange(1,3,.01)
x3 = arange(3,4,.01)
x4 =arange(4,6,.01)
p1 = ra*x1;
p2 = ra*x2-4*(x2-1);
p3 = ra*x3-4*(x3-1)-10*(x3-3);
p4 = ra*x4-4*(x4-1)-10*(x4-3)-8*(x4-4);
plt.plot(x1,p1,x2,p2,x3,p3,x4,p4)

plt.show()