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 workfor i in employees:    print(i['title'])employees.count('title')print()#my output:MrMrMrsMs#expected output:{'Ms': 1, 'Mrs': 1, 'Mr': 2}

Answer 1

collections.Counter

from collections import Counter

counts = 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 defaultdict

result = defaultdict(int)

for i in employees:

    result[i["title"]] += 1

print(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 Counter

titles = [e['title'] for e in employees]

counts = Counter(titles)

# Counter({'Mr': 2, 'Mrs': 1, 'Ms': 1})