Python - 每个键的唯一值计数

给定一个字典列表，任务是编写一个Python程序来计算每个键的唯一值。

例子：

Input : test_list = [{“gfg” : 1, “is” : 3, “best”: 2}, {“gfg” : 1, “is” : 3, “best” : 6}, 

{“gfg” : 7, “is” : 3, “best” : 10}]

Output : {‘gfg’: 2, ‘is’: 1, ‘best’: 3}

Explanation : gfg has 1 and 7 as unique elements, hence 2.

Input : test_list = [{“gfg” : 1, “is” : 3, “best”: 2}, {“gfg” : 1, “is” : 3, “best” : 6},

 {“gfg” : 1, “is” : 3, “best” : 10}]

Output : {‘gfg’: 1, ‘is’: 1, ‘best’: 3}

Explanation : gfg has only 1 as unique element, hence 1.

方法 #1：使用len() + set() + 循环

在这种情况下，使用 set() 提取唯一值，使用 len() 获取其计数，然后将结果映射到使用 keys() 提取的每个键。迭代键发生在循环中。

Python3

# Python3 code to demonstrate working of
# Unique values count of each Key
# Using len() + set()
  
# initializing lists
test_list = [{"gfg": 1, "is": 3, "best": 2}, {
    "gfg": 1, "is": 3, "best": 6}, {"gfg": 7, "is": 3, "best": 10}]
  
# printing original list
print("The original list is : " + str(test_list))
  
res = dict()
for key in test_list[0].keys():
  
    # mapping unique values.
    res[key] = len(set([sub[key] for sub in test_list]))
  
# printing result
print("Unique count of keys : " + str(res))

输出：

The original list is : [{‘gfg’: 1, ‘is’: 3, ‘best’: 2}, {‘gfg’: 1, ‘is’: 3, ‘best’: 6},

 {‘gfg’: 7, ‘is’: 3, ‘best’: 10}]

Unique count of keys : {‘gfg’: 2, ‘is’: 1, ‘best’: 3}

方法 #2：使用字典理解 + len() + set()

与上述方法类似，不同之处在于字典理解被用作速记的一种线性替代方法。

蟒蛇3

# Python3 code to demonstrate working of
# Unique values count of each Key
# Using len() + set() + dictionary comprehension
  
# initializing lists
test_list = [{"gfg": 1, "is": 3, "best": 2}, {
    "gfg": 1, "is": 3, "best": 6}, {"gfg": 7, "is": 3, "best": 10}]
  
# printing original list
print("The original list is : " + str(test_list))
  
# dictionary comprehension for compact solution
res = {key: len(set([sub[key] for sub in test_list]))
       for key in test_list[0].keys()}
  
# printing result
print("Unique count of keys : " + str(res))

输出：

The original list is : [{‘gfg’: 1, ‘is’: 3, ‘best’: 2}, {‘gfg’: 1, ‘is’: 3, ‘best’: 6},

 {‘gfg’: 7, ‘is’: 3, ‘best’: 10}]

Unique count of keys : {‘gfg’: 2, ‘is’: 1, ‘best’: 3}