Python–从列表中创建字典

原文:https://www . geesforgeks . org/python-create-dictionary-from-list/

给定一个列表。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。

示例:

输入:test _ list =[“gfg”,“is”,“best”],K =“pref _” 输出 : {'pref_gfg': 'gfg ',' pref_is': 'is ',' pref_best': 'best'} 解释:连接 K 后构造的键

输入:test _ list =[“gfg”、“best”],K =“pref _” 输出:{‘pref _ gfg’:‘gfg’,‘pref _ best’:‘best’} 解释:串接 K 后构造的按键

方法#1:使用循环

这是执行这项任务的方法之一。在这种情况下,我们使用+运算符执行串联来构造键,并从列表中提取值。

Python 3

# 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:

原始列表为:['gfg ',' is ',' best'] 构造的字典:{'def_key_gfg': 'gfg ',' def_key_is': 'is ',' def_key_best': 'best'}

方法二:使用 词典理解

这是执行这项任务的另一种方式。在这篇文章中,我们使用字典理解来构建一个使用一行的字典。

Python 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:

原始列表为:['gfg ',' is ',' best'] 构造的字典:{'def_key_gfg': 'gfg ',' def_key_is': 'is ',' def_key_best': 'best'}