from scipy import linspace
from scipy.stats import binom
import matplotlib.pyplot as plt
n,p=30,0.5
x=linspace(0,n)
for x in range(-1,n+1):
  y=binom.cdf(x+0.5,n,p)
  plt.plot([x,x+1],[y,y],color='blue') # lépcsős fv!
plt.plot([-3,0],[0,0],color='red')
plt.plot([n,n+3],[1,1],color='red')


plt.show()