even my man

import numpy as np
import matplotlib.pyplot as plt

def f(x):
    return 2*np.sin(x) + 5/2

x= np.linspace(1, 20,  1000)
y = f(x)
y[y >= 4] = 4
y[y <= 1 ] = 1

    
        
plt.figure()
plt.plot(x, y, linewidth=3)
plt.show()