import numpy as np
import matplotlib.pyplot as plt
from scipy.stats import chi2

#x-axis ranges from 0 to 20 with .001 steps
x = np.arange(0, 20, 0.001)

#define multiple Chi-square distributions

plt.plot(x, chi2.pdf(x, df=4), label='df: 4')
plt.plot(x, chi2.pdf(x, df=6), label='df: 6') 
plt.plot(x, chi2.pdf(x, df=8), label='df: 8') 

#add legend to plot
plt.legend()