old_contents: # Bubble sort python implementation
  
  def bubble_sort(arr):
  	length = len(arr)
  
  	for i in range(length):
  
  		for j in range(0, length-i-1):
  			if arr[j] > arr[j+1]:
  				temp = arr[j]
  				arr[j] = arr[j+1]
  				arr[j] = temp
  
  	return arr
  
new_contents: # Bubble sort python implementation
  
  def bubble_sort(arr):
  	length = len(arr)
  
  	for i in range(length): # go through all elements in array
  
  		for j in range(0, length-i-1): # last i elements are already in place
  			if arr[j] > arr[j+1]:
  				arr[j], arr[j+1] = arr[j+1], arr[j] # swap if element being looked at is greater than element adjacent to the right
  
  	return arr
  
  
  # test cases
  arr_one = [5, 4, 3, 2, 1]
  arr_two = [5, 4, 3, 1, 2]
  arr_three = [5, 4, 1, 3, 2]
  arr_four = [5, 4, 1, 2, 3]
  arr_five = [1, 2, 3, 4, 5]
  
  print bubble_sort(arr_one) # prints [1, 2, 3, 4, 5]
  print bubble_sort(arr_two) # prints [1, 2, 3, 4, 5]
  print bubble_sort(arr_three) # prints [1, 2, 3, 4, 5]
  print bubble_sort(arr_four) # prints [1, 2, 3, 4, 5]
  print bubble_sort(arr_five) # prints [1, 2, 3, 4, 5]
  
subject: Add test cases