Python|获取字典中给定值 N 的键数

在本文中，我们将看到如何获取给定字典中具有给定值 N 的键的数量。有多种方法可以完成此任务。让我们借助示例来了解它们。

简单的方法——

# Python3 code to Get the number of keys
# with given value N in dictionary
  
# Initialize dictionary 
test_dict = {'gfg' : 1, 'is' : 2, 'best' : 3, 'for' : 2, 'CS' : 2} 
  
  
# printing original dictionary 
print("The original dictionary : " + str(test_dict)) 
  
# Initialize value 
N = 2
  
# Using loop 
# Selective key values in dictionary 
res = 0
for key in test_dict: 
    if test_dict[key] == N: 
        res = res + 1
      
# printing result 
print("Frequency of N is : " + str(res)) 

输出：

The original dictionary : {'CS': 2, 'for': 2, 'is': 2, 'gfg': 1, 'best': 3}
Frequency of N is : 3

方法 #2：使用 sum() + values()

# Python3 code to Get the number of keys
# with given value N in dictionary
# Using sum() + values() 
  
# Initialize dictionary 
test_dict = {'gfg' : 1, 'is' : 2, 'best' : 3, 'for' : 2, 'CS' : 2} 
  
# printing original dictionary 
print("The original dictionary : " + str(test_dict)) 
  
# Initialize value 
N = 2
  
# Using sum() + values() 
# Selective key values in dictionary
res = sum(x == N for x in test_dict.values()) 
      
# printing result 
print("Frequency of K is : " + str(res)) 

输出：

The original dictionary : {'is': 2, 'for': 2, 'gfg': 1, 'best': 3, 'CS': 2}
Frequency of K is : 3