input: Write a function to prompt the user to enter the value of radius to calculate the area of a circle. The function should return the calculated area. If the radius entered is 0, the function should return 0.
  assert calculate_circle_area() == 0
  assert calculate_circle_area() == 12.56
  assert calculate_circle_area() == 78.5
  assert calculate_circle_area() == 314.0
  assert calculate_circle_area() == 0
output: def calculate_circle_area():
      radius = float(input("Enter the radius: "))
      if radius == 0:
          return 0
      return 3.14 * radius * radius