In [1]:
from math import pi

In [7]:
user_input = input("enter radius ")


enter radius 1

In [12]:
r = int(user_input)
if r < 0:
    print("enter a positive value for the radius")
else:
    
    vi = 1.33 * pi * r * r * r
print(vi)


4.178318229274425

In [ ]: