Python - 追加其他列表中的缺失元素

给定 2 个列表，将列表 1 中缺少的元素追加到列表 2。

Input : test_list1 = [5, 6, 4, 8, 9, 1], test_list2 = [9, 8, 10]
Output : [5, 6, 4, 1, 9, 8, 10]
Explanation : 5, 6, 4, 1 added to list 2, in order.

Input : test_list1 = [5, 6, 4, 8, 9, 1], test_list2 = [9, 10]
Output : [5, 6, 4, 8, 1, 9, 10]
Explanation : 5, 6, 4, 8, 1 added to list 2, in order.

方法#1：使用列表推导

在此，我们迭代列表 1 以检查列表 2 中缺失的元素，然后将这些元素添加到列表 2。

Python3

# Python3 code to demonstrate working of 
# Append Missing elements from other List
# Using list comprehension
  
# initializing list
test_list1 = [5, 6, 4, 8, 9, 1]
test_list2 = [9, 8, 7]
  
# printing original lists
print("The original list 1 is : " + str(test_list1))
print("The original list 2 is : " + str(test_list2))
  
# extracting elements from list 1 which are not in list 2
temp1 = [ele for ele in test_list1 if ele not in test_list2]
  
# constructing result 
res = temp1 + test_list2
  
# printing result 
print("The modified list 2 : " + str(res))

输出

The original list 1 is : [5, 6, 4, 8, 9, 1]
The original list 2 is : [9, 8, 7]
The modified list 2 : [5, 6, 4, 1, 9, 8, 7]

方法 #2：使用 set() + “-”运算符+ extend()

在此，我们使用 set() 和 –运算符检查列表 2 中缺少的列表 1 的元素，并使用 extend() 来连接两个列表以获得所需的结果。

Python3

# Python3 code to demonstrate working of 
# Append Missing elements from other List
# Using set() + "-" operator + extend()
  
# initializing list
test_list1 = [5, 6, 4, 8, 9, 1]
test_list2 = [9, 8, 7]
  
# printing original lists
print("The original list 1 is : " + str(test_list1))
print("The original list 2 is : " + str(test_list2))
  
# finding missing words
rem_list = (set(test_list1) - set(test_list2))
  
# checking order
res = [ele for ele in test_list1 if ele in rem_list] 
  
# joining result
res.extend(test_list2)
  
# printing result 
print("The modified list 2 : " + str(res))

输出

The original list 1 is : [5, 6, 4, 8, 9, 1]
The original list 2 is : [9, 8, 7]
The modified list 2 : [5, 6, 4, 1, 9, 8, 7]