input: Write a function to compute the area of a circle with the given radius. The function should return the area as a float. If the radius is less than or equal to zero, return 0.0.
  
  def area_circle(radius):
   if radius <= 0:
   return 0.0
   return math.pi * (radius ** 2)
  
  assert area_circle(5) == 78.54
  assert area_circle(0) == 0.0
  assert area_circle(-3) == 0.0
output: def area_circle(radius):
   if radius <= 0:
    return 0.0
   return math.pi * (radius ** 2)