錯誤是因為只能將列表（而不是“NoneType”）連接到列表中

Question

我想顛倒 Jamies_list 和 Drews 列表應該放在第一位，然后附上列表，我想返回完整列表。

def combine_lists(list1, list2):
  # Generate a new list containing the elements of list2
  # Followed by the elements of list1 in reverse order
  return(list2+list1.reverse())
    
Jamies_list = ["Alice", "Cindy", "Bobby", "Jan", "Peter"]
Drews_list = ["Mike", "Carol", "Greg", "Marcia"]

print(combine_lists(Jamies_list, Drews_list))

Answer 1

.reverse()是就地操作。 它不會返回反向列表，它返回None

使用sorted(list1, reverse=True) 。

def combine_lists(list1, list2):
  # Generate a new list containing the elements of list2
  # Followed by the elements of list1 in reverse order
  return(list2+sorted(list1, reverse=True))
    
Jamies_list = ["Alice", "Cindy", "Bobby", "Jan", "Peter"]
Drews_list = ["Mike", "Carol", "Greg", "Marcia"]

print(combine_lists(Jamies_list, Drews_list))

別的

def combine_lists(list1, list2):
  # Generate a new list containing the elements of list2
  # Followed by the elements of list1 in reverse order
  list1.reverse()
  return(list2+list1)
    
Jamies_list = ["Alice", "Cindy", "Bobby", "Jan", "Peter"]
Drews_list = ["Mike", "Carol", "Greg", "Marcia"]

print(combine_lists(Jamies_list, Drews_list))

別的

def combine_lists(list1, list2):
  # Generate a new list containing the elements of list2
  # Followed by the elements of list1 in reverse order
  return list2 + list1[::-1]
    
Jamies_list = ["Alice", "Cindy", "Bobby", "Jan", "Peter"]
Drews_list = ["Mike", "Carol", "Greg", "Marcia"]

print(combine_lists(Jamies_list, Drews_list))

Answer 2

reverse()是 Python 編程語言中的內置方法，可將列表的對象反轉到位

您也可以使用 print(list1.reverse()) 來檢查它。 它將打印無。

所以建議使用return list2 + list1[::-1]