input: Write a function to calculate the distance between two points on a two-dimensional plane. The function should take in four parameters: x1, y1, x2, and y2, which represent the coordinates of the two points. The function should return the distance as a float.
  assert calc_distance(3, 4, -9, -2) == 13.601470508735444
  assert calc_distance(1, 1, 1, 1) == 0.0
  assert calc_distance(5, 2, -2, -3) == 9.219544457292887
  assert calc_distance(-3, -4, -3, 3) == 7.0
output: def calc_distance(x1, y1, x2, y2):
      return ((x2 - x1) ** 2 + (y2 - y1) ** 2) ** 0.5