Python – 为字典中的每个键名添加前缀

给定一个字典，通过为每个键添加前缀来更新它的每个键。

Input : test_dict = {‘Gfg’ : 6, ‘is’ : 7, ‘best’ : 9}, temp = “Pro”
Output : {‘ProGfg’ : 6, ‘Prois’ : 7, ‘Probest’ : 9}
Explanation : “Pro” prefix added to each key.

Input : test_dict = {‘Gfg’ : 6, ‘is’ : 7, ‘best’ : 9}, temp = “a”
Output : {‘aGfg’ : 6, ‘ais’ : 7, ‘abest’ : 9}
Explanation : “a” prefix added to each key.

方法#1：使用字典理解

这是可以执行此任务的方法之一。在此，我们通过执行前缀与所有键的连接来构造新字典。

Python3

# Python3 code to demonstrate working of 
# Add prefix to each key name in dictionary
# Using loop
  
# initializing dictionary
test_dict = {'Gfg' : 6, 'is' : 7, 'best' : 9, 'for' : 8, 'geeks' : 11} 
  
# printing original dictionary
print("The original dictionary is : " + str(test_dict))
  
# initializing prefix 
temp = "Pro"
  
# + operator is used to perform task of concatenation
res = {temp + str(key): val for key, val in test_dict.items()}
  
# printing result 
print("The extracted dictionary : " + str(res))

输出

The original dictionary is : {'Gfg': 6, 'is': 7, 'best': 9, 'for': 8, 'geeks': 11}
The extracted dictionary : {'ProGfg': 6, 'Prois': 7, 'Probest': 9, 'Profor': 8, 'Progeeks': 11}

方法#2：使用 f字符串+ 字典理解

上述功能的组合可以用来解决这个问题。在此，我们使用 f 个字符串执行连接任务。仅适用于 >=3.6 版本的Python。

Python3

# Python3 code to demonstrate working of 
# Add prefix to each key name in dictionary
# Using f strings + dictionary comprehension
  
# initializing dictionary
test_dict = {'Gfg' : 6, 'is' : 7, 'best' : 9, 'for' : 8, 'geeks' : 11} 
  
# printing original dictionary
print("The original dictionary is : " + str(test_dict))
  
# initializing prefix 
temp = "Pro"
  
# dictionary comprehension is used to bind result 
# f strings are used to bind prefix with key
res = {f"Pro{key}": val for key, val in test_dict.items()}
  
# printing result 
print("The extracted dictionary : " + str(res)) 

输出

The original dictionary is : {'Gfg': 6, 'is': 7, 'best': 9, 'for': 8, 'geeks': 11}
The extracted dictionary : {'ProGfg': 6, 'Prois': 7, 'Probest': 9, 'Profor': 8, 'Progeeks': 11}