我如何计算字典中每个标题的数量

Question

我一直试图弄清楚它有一段时间了，而不是最擅长编程。这是我到目前为止所拥有的。

字典的键应该是列表中员工的头衔，值是具有该特定头衔的员工数。

employees = [

    {

        "email": "[e-mail]",

        "employee_id": 101,

        "firstname": "Jonathan",

        "lastname": "Calderon",

        "title": "Mr",

        "work_phone": "[phone]"

    },

    {

        "email": "[e-mail]",

        "employee_id": 102,

        "firstname": "Christopher",

        "lastname": "Hansen",

        "title": "Mr",

        "work_phone": "[phone]"

    },

    {

        "email": "[e-mail]",

        "employee_id": 103,

        "firstname": "Isabella",

        "lastname": "Dorsey",

        "title": "Mrs",

        "work_phone": "[phone]"

    },

    {

        "email": "[e-mail]",

        "employee_id": 104,

        "firstname": "Barbara",

        "lastname": "Baker",

        "title": "Ms",

        "work_phone": "[phone]"

    }

]

#my work

for i in employees:

    print(i['title'])

employees.count('title')

print()

#my output:

Mr

Mr

Mrs

Ms

#expected output:

{'Ms': 1, 'Mrs': 1, 'Mr': 2}

Answer 1

collections.Counterfrom collections import Countercounts = Counter([x['title'] for x in employees])print(counts)# Counter({'Mr': 2, 'Mrs': 1, 'Ms': 1})如果有任何没有title字段的记录，请使用：counts = Counter([x.get("title", None) for x in employees])# Counter({'Mr': 2, 'Mrs': 1, 'Ms': 1, None: 1})在这里，如果不存在，.get将获取title或返回的值。Nonetitle

Answer 2

使用 collections.defaultdict前任：from collections import defaultdictresult = defaultdict(int)for i in employees:&nbsp; &nbsp; result[i["title"]] += 1print(result)输出：defaultdict(<type 'int'>, {'Mrs': 1, 'Ms': 1, 'Mr': 2})

Answer 3

你可以用一个计数器来做到这一点：from collection import Countertitles = [e['title'] for e in employees]counts = Counter(titles)# Counter({'Mr': 2, 'Mrs': 1, 'Ms': 1})