input: Write a function to calculate the distance between two points using the Euclidean distance formula. The function should take four parameters representing the coordinates of the two points and return the distance.
  
  import math
  
  def distance_between_points(x1, y1, x2, y2):
      return math.sqrt((x2 - x1)**2 + (y2 - y1)**2)
  
  assert distance_between_points(2, 7, 4, 9) == 2.8284271247461903
  assert distance_between_points(0, 0, 3, 4) == 5.0
  assert distance_between_points(-1, -1, 2, 3) == 5.0
  assert distance_between_points(1, 1, 1, 1) == 0.0
  assert distance_between_points(5, 5, -5, -5) == 14.142135623730951
output: import math
  
  def distance_between_points(x1, y1, x2, y2):
      return math.sqrt((x2 - x1)**2 + (y2 - y1)**2)