python 中员工字典数据库中的计数值

Question

python 对我来说是新语言，所以这个问题听起来很简单，但如果有人能指出正确的方向，我将不胜感激！我创建了一个名为 employees 的字典，它对他们有一些价值：

我想知道每个部门有多少人，例如：tech-2，accounting-1。

我有这样的东西，但它打印出来是空白的。

  def main():
   employees= {'name': 'John', 'empID': '102', 'dpt': 'tech', 'title': 
   'programmer', 'salary': '75'}
   {'name': 'Jane', 'empID': '202', 'dpt': 'tech', 'title': 'programmer', 
   'salary': '80'}
   {'name': 'Joe', 'empID': '303', 'dpt': 'accounting', 'title': 
   'accountant', 'salary': '85'}
    for item in employees:
    dic = employees[item]
    if dic['dpt'[0]]==dic['dpt'[1]]:
        duplicate += 1
        print("there are "+ duplicate)
    else:
        print("There are no duplicate")

Answer 1

如果您不想导入 Counter，请使用字典来跟踪每个部门的员工人数：

employee_list = [{
    'name': 'John',
    'empID': '102',
    'dpt': 'tech',
    'title': 'programmer',
    'salary': '75'
}, {
    'name': 'Jane',
    'empID': '202',
    'dpt': 'tech',
    'title': 'programmer',
    'salary': '80'
}, {
    'name': 'Joe',
    'empID': '303',
    'dpt': 'accounting',
    'title': 'accountant',
    'salary': '85'
}]

department_to_count = dict()
for employee in employee_list:
    department = employee["dpt"]

    if department not in department_to_count:
        department_to_count[department] = 0

    department_to_count[department] += 1

for department, employee_count in department_to_count.items():
    print("Department {} has {} employees".format(department,
                                                  employee_count))

Answer 2

使用collections.Counter:

from collections import Counter

employees = [{'name': 'John', 'empID': '102', 'dpt': 'tech', 'title': 'programmer', 'salary': '75'},
             {'name': 'Jane', 'empID': '202', 'dpt': 'tech', 'title': 'programmer', 'salary': '80'},
             {'name': 'Joe', 'empID': '303', 'dpt': 'accounting', 'title': 'accountant', 'salary': '85'}]

dpts = [x['dpt'] for x in employees]
print(Counter(dpts))

# Counter({'tech': 2, 'accounting': 1})

Answer 3

试试这个：

def main():
    duplicate = 0
    employees = [
        {'name': 'John', 'empID': '102', 'dpt': 'tech', 'title': 'programmer', 'salary': '75'},
        {'name': 'Jane', 'empID': '202', 'dpt': 'tech', 'title': 'programmer', 'salary': '80'},
        {'name': 'Joe', 'empID': '303', 'dpt': 'accounting', 'title': 'accountant', 'salary': '85'}
    ]
    tech_dep = 0
    accounting_dep = 0
    for item in employees:
        if item['dpt'] == 'tech':
            tech_dep += 1
        elif item['dpt'] == 'accounting':
            accounting_dep += 1

    print('Number of Employees from tech dep are : ', tech_dep)
    print('Number of Employees from accounting dep are : ', accounting_dep)


main()

它会给你这样的输出：

Number of Employees from tech dep are :  2
Number of Employees from accounting dep are :  1

注：

这是对您问题的简单回答，因为正如您所说，您是 python 的新手，所以我只想给您简单的回答！另请注意，您在问题中创建字典的方式是错误的，您可以制作字典字典或字典列表。而且@Austin刚刚给你的答案也很简单，说明了counter的使用

希望对您有所帮助！ :)

Answer 4

如果您正在寻找一个特定键的总数，您可以使用 .count() list method 作为直接查询。

给定一个字典列表：

>>> employees = [{'name': 'John', 'empID': '102', 'dpt': 'tech', 'title': 'programmer', 'salary': '75'},
         {'name': 'Jane', 'empID': '202', 'dpt': 'tech', 'title': 'programmer', 'salary': '80'},
         {'name': 'Joe', 'empID': '303', 'dpt': 'accounting', 'title': 'accountant', 'salary': '85'}]

您可以使用列表理解创建每个列表：

>>> [d['dpt'] for d in employees]
['tech', 'tech', 'accounting']

然后可以统计：

>>> [d['dpt'] for d in employees].count('tech')
2
>>> [d['dpt'] for d in employees].count('accounting')
1
>>> [d['dpt'] for d in employees].count('nothing')
0

或者，您可以构造一个生成器来计算特定值：

>>> sum(1 for d in employees if d['dpt']=='tech')
2

如果你想获得所有元素的计数（除了使用计数器）你可以这样做：

>>> lot=[d['dpt'] for d in employees]
>>> {c:lot.count(c) for c in set(lot)}
{'accounting': 1, 'tech': 2}

python 中员工字典数据库中的计数值

Counting values in an employee dictionary database in python

python

counter

dictionary

key-value

python-3.x