Plot complex function using TikZ & Python

fun.py

import numpy as np

def coth(x):
    return np.cosh(x)/np.sinh(x)

def brilloutin(J, x):
    if x == 0:
        return 0
    else:
        return (2*J+1)/(2*J)*coth((2*J+1)/(2*J)*x) - 1/(2*J)*coth(1/(2*J)*x)

x = np.linspace(-5, 10, 1000)
y = np.zeros((len(x)))
for i in range(0, len(x)):
    y[i] = brilloutin(1, x[i])

datafile = np.savetxt('data.dat', np.column_stack((x, y)))

fun.tex

\documentclass[tikz,border=10pt]{standalone}

\begin{document}
\begin{tikzpicture}[
    scale=3,
    xscale=0.2,]
  \draw[->] (-5,0) -- (10,0);
  \draw[->] (0,-1) -- (0,1.5);
  \draw plot file {data.dat};
\end{tikzpicture}
\end{document}