Function Arguments

# Here, an empty list is used as a default argument of the function.
def append(number, number_list=[]):
  number_list.append(number)
  print(number_list)
  return number_list

# Below are 3 calls to the `append` function and their expected and actual outputs:
append(5) # expecting: [5], actual: [5]
append(7) # expecting: [7], actual: [5, 7]
append(2) # expecting: [2], actual: [5, 7, 2]