input: 
  class create_3d_vector_class:
      """Create a Python class named Vector3D which represents a 3D Vector.
      The class should have an initializer to set the x, y, and z components.
      It should also have a __str__ method to return the vector in the format (x, y, z).
      Example:
      >>> v = Vector3D(1, 2, 3)
      >>> print(v)
      (1, 2, 3)
      """
  
output:     
      def __init__(self, x, y, z):
          self.x = x
          self.y = y
          self.z = z
  
      def __str__(self):
          return f"({self.x}, {self.y}, {self.z})"
  