Python – 将键值分配给值列表字典中的列表元素

给定元素列表，将它们与值列表中匹配值的键映射。

Input : test_list = [4, 6, 3, 5, 3], test_dict = {“Gfg” : [5, 3, 6], “is” : [8, 4]}
Output : [‘is’, ‘Gfg’, ‘Gfg’, ‘Gfg’, ‘Gfg’]
Explanation : 4 is present in “is” key, hence mapped in new list.

Input : test_list = [6, 3, 5, 3], test_dict = {“Gfg” : [5, 3, 6], “is” : [18, 14]}
Output : [‘Gfg’, ‘Gfg’, ‘Gfg’, ‘Gfg’]
Explanation : All elements present in “Gfg” key.

方法#1：使用列表推导

这是可以执行此任务的方式之一。在此，我们提取字典值列表的每个元素以检查列表值的出现，如果匹配，我们将该键的值分配给该索引。

Python3

# Python3 code to demonstrate working of 
# Assigning Key values to list elements from Value list Dictionary
# Using list comprehension
  
# initializing list
test_list = [4, 6, 3, 10, 5, 3]
  
# printing original list
print("The original list : " + str(test_list))
  
# initializing dictionary 
test_dict = {"Gfg" : [5, 3, 6], "is" : [8, 4], "Best" : [10, 11]}
  
# nested loop inside list comprehension to check each key 
res = [key for ele in test_list
       for key, val in test_dict.items() if ele in val]
  
# printing result 
print("The filtered list : " + str(res))

输出

The original list : [4, 6, 3, 10, 5, 3]
The filtered list : ['is', 'Gfg', 'Gfg', 'Best', 'Gfg', 'Gfg']

方法#2：使用字典理解+列表理解

这是可以执行此任务的另一种方式。在此我们创建逆字典，并将每个列表值与其键映射，然后将每个键映射到参数键列表元素以匹配键值。

Python3

# Python3 code to demonstrate working of 
# Assigning Key values to list elements from Value list Dictionary
# Using dictionary comprehension + list comprehension
  
# initializing list
test_list = [4, 6, 3, 10, 5, 3]
  
# printing original list
print("The original list : " + str(test_list))
  
# initializing dictionary 
test_dict = {"Gfg" : [5, 3, 6], "is" : [8, 4], "Best" : [10, 11]}
  
# creating inverse dictionary of elements 
temp = {j : i for i, k in test_dict.items() for j in k}
  
# creating end result by mapping elements
res = [temp.get(key) for key in test_list]
  
# printing result 
print("The filtered list : " + str(res))

输出

The original list : [4, 6, 3, 10, 5, 3]
The filtered list : ['is', 'Gfg', 'Gfg', 'Best', 'Gfg', 'Gfg']