input: Write a function to calculate the distance between two points using the Euclidean distance formula. The function should take four parameters: the x and y coordinates of the first point (x1, y1) and the x and y coordinates of the second point (x2, y2). Return the calculated 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) == math.sqrt(8)
  assert distance_between_points(0, 0, 3, 4) == 5.0
  assert distance_between_points(1, 1, 1, 1) == 0.0
  assert distance_between_points(0, 0, 0, 5) == 5.0
  assert distance_between_points(-2, -5, -2, -5) == 0.0
output: import math
  
  def distance_between_points(x1, y1, x2, y2):
      return math.sqrt((x2 - x1)**2 + (y2 - y1)**2)