Python - 从列表中创建字典

给出一个列表。任务是将其转换为字典，其中值作为列表元素，键作为给定字符串K 和值的串联。

例子：

Input : test_list = [“gfg”, “is”, “best”], K = “pref_” 
Output : {‘pref_gfg’: ‘gfg’, ‘pref_is’: ‘is’, ‘pref_best’: ‘best’} 
Explanation : Keys constructed after concatenating K.

Input : test_list = [“gfg”, “best”], K = “pref_” 
Output : {‘pref_gfg’: ‘gfg’, ‘pref_best’: ‘best’} 
Explanation : Keys constructed after concatenating K. 

方法#1：使用循环

这是可以执行此任务的方法之一。在此，我们使用 +运算符执行连接以构造键，并从列表中提取值。

Python3

# Python3 code to demonstrate working of 
# Values derived Dictionary keys
# Using loop
  
# initializing list
test_list = ["gfg", "is", "best"] 
  
# printing original list
print("The original list is : " + str(test_list))
  
# initializing K 
K = "def_key_"
  
# using loop to construct new Dictionary
# + operator used to concat default key and values 
res = dict()
for ele in test_list:
    res[K + str(ele)] = ele 
  
# printing result 
print("The constructed Dictionary : " + str(res))

输出：

The original list is : [‘gfg’, ‘is’, ‘best’]
The constructed Dictionary : {‘def_key_gfg’: ‘gfg’, ‘def_key_is’: ‘is’, ‘def_key_best’: ‘best’}

方法#2：使用字典理解

这是可以执行此任务的另一种方式。在此，我们使用字典理解使用单行构建字典。

蟒蛇3

# Python3 code to demonstrate working of 
# Values derived Dictionary keys
# Using dictionary comprehension
  
# initializing list
test_list = ["gfg", "is", "best"] 
  
# printing original list
print("The original list is : " + str(test_list))
  
# initializing K 
K = "def_key_"
  
# using dictionary comprehension
# + operator used to concat default key and values 
res = {K + str(ele) : ele for ele in test_list}
  
# printing result 
print("The constructed Dictionary : " + str(res))

输出：

The original list is : [‘gfg’, ‘is’, ‘best’]
The constructed Dictionary : {‘def_key_gfg’: ‘gfg’, ‘def_key_is’: ‘is’, ‘def_key_best’: ‘best’}