In [1]: from sympy import *

In [2]: import numpy as np

In [3]: x = Symbol('x')

In [4]: y = x**2 + 1

In [5]: yprime = y.diff(x)

In [6]: yprime

Out[6]: 2⋅x

​

In [7]: f = lambdify(x, yprime, 'numpy')

In [8]: f(np.ones(5))

Out[8]: [ 2.  2.  2.  2.  2.]