Why am I receiving a syntax error for defining a variable?

  numerical-methods, python, scipy, syntax, syntax-error

I have never used stack overflow before and am unsure whether asking for help identifying errors is appropriate to ask but I shall ask anyway. I am writing a script to numerically integrate a particular function using trapezoid from the Scipy library. My code is below:

from scipy.integrate import trapezoid
import numpy as np

def T(x):
    return 4*np.sqrt(1/c)*(1/(np.sqrt(1-k**2*(np.sin(x))**2))

x0 = 3 
k = np.sin(x0/2)
c = 7/4

x = np.linspace(0,np.pi/2,10)

Int = trapezoid(T(x), x)


I am receiving an error on line 7:

x0 = 3

saying invalid syntax though I cannot work out why. Any help identifying the issue would be greatly appreciated!

Source: Python Questions