from sympy import *

x = symbols('x')

y = x ** 3 + x ** 2 + 1

# 　表达式求值
for i in range(3):
    print(y.evalf(subs={x: i}))

# 求导
print(diff(y, x))
for i in range(3):
    print(diff(y, x).evalf(subs={x: i}))

1.00000000000000
3.00000000000000
13.0000000000000
3*x**2 + 2*x
0
5.00000000000000
16.0000000000000