Python - 在字典中交换第 i 个和第 j 个键的值

给定一个字典，交换第 i 个和第 j 个索引键的值。

Input : test_dict = {“Gfg”: 2, “is”: 4, “best”: 7, “for”: 9, “geeks”: 10}, i, j = 1, 4 
Output : {‘Gfg’: 2, ‘is’: 10, ‘best’: 7, ‘for’: 9, ‘geeks’: 4} 
Explanation : Values of “is” and “geeks” swapped.

Input : test_dict = {“Gfg”: 2, “is”: 4, “best”: 7, “for”: 9, “geeks”: 10}, i, j = 1, 2 
Output : {‘Gfg’: 2, ‘is’: 7, ‘best’: 4, ‘for’: 9, ‘geeks’: 10} 
Explanation : Values of “is” and “best” swapped. 

方法 #1：使用循环 + values()

这是可以执行此任务的方法之一。在这里，我们获得所需的交换键的值并在循环中执行所需的交换，这将创建一个新字典。

Python3

# Python3 code to demonstrate working of 
# Swap ith and jth key's value in dictionary
# Using loop + values()
  
# initializing dictionary
test_dict = {"Gfg": 2, "is": 4, "best": 7,
             "for": 9, "geeks": 10}
  
# printing original dictionary
print("The original dictionary is : " + str(test_dict))
  
# initializing i, j 
i, j = 1, 3
  
# Extracting keys 
vals = list(test_dict.values())
  
# performing swap 
vals[i], vals[j] = vals[j], vals[i]
  
# setting new values 
res = dict()
for idx, key in enumerate(test_dict):
    res[key] = vals[idx]
      
# printing result 
print("Required dictionary : " + str(res))

输出：

The original dictionary is : {‘Gfg’: 2, ‘is’: 4, ‘best’: 7, ‘for’: 9, ‘geeks’: 10}
Required dictionary : {‘Gfg’: 2, ‘is’: 9, ‘best’: 7, ‘for’: 4, ‘geeks’: 10}

方法#2：使用 values() + 字典理解

这是可以执行此任务的方法之一。这是一种与上面类似的方法，不同之处在于字典分配步骤是使用字典理解来执行的。

蟒蛇3

# Python3 code to demonstrate working of 
# Swap ith and jth key's value in dictionary
# Using values() + dictionary comprehension
  
# initializing dictionary
test_dict = {"Gfg": 2, "is": 4, "best": 7, 
             "for": 9, "geeks": 10}
  
# printing original dictionary
print("The original dictionary is : " + str(test_dict))
  
# initializing i, j 
i, j = 1, 3
  
# Extracting keys 
vals = list(test_dict.values())
  
# performing swap 
vals[i], vals[j] = vals[j], vals[i]
  
# setting new values 
res = {key : vals[idx] for idx, key in enumerate(test_dict)}
      
# printing result 
print("Required dictionary : " + str(res)) 

输出：

The original dictionary is : {‘Gfg’: 2, ‘is’: 4, ‘best’: 7, ‘for’: 9, ‘geeks’: 10}
Required dictionary : {‘Gfg’: 2, ‘is’: 9, ‘best’: 7, ‘for’: 4, ‘geeks’: 10}