如何计算每个年龄的人数(Django)

Question

我有

class Person(TimeStampedModel, Address):
    name = models.CharField(_('nome'), max_length=100)
    birthday = models.DateField(_('data de nascimento'))

和这个函数

import datetime
from datetime import date
'''
http://keyes.ie/calculate-age-with-python/
'''

def age(when, on=None):
    if on is None:
        on = datetime.date.today()
    was_earlier = (on.month, on.day) < (when.month, when.day)
    return on.year - when.year - (was_earlier)
age(date(2000, 1, 1))

按年龄计算人数

age quant
20-25   89
25-30   100
30-35   90
35-40   102

我知道我必须使用注释和计数，但不知道从哪里开始。

Answer 1

在您的示例中，我将使用2个函数，一个用于获取人员的年龄，另一个用于准备一个字典，该字典返回按年龄范围分组的人员。

def calculate_age(born):
    today = date.today()
    return today.year - born.year - ((today.month, today.day) < (born.month, born.day))
def get_persons_grouped_by_age():
    age_dict = {
        "under_20": [],
        "20_25": [],
        "25_30": [],
        "30_35": [],
        "35_40": [],
        "over_40": [],
    }
    for person in Person.objects.all():
        person_age = calculate_age(person.birthday)
        if person_age < 20:
           age_dict["under_20"].append(person)
        if 20 <= person_age < 25:
           age_dict["20_25"].append(person)
        elif 25 <= person_age < 30:
           age_dict["25_30"].append(person)
        elif 30 <= person_age < 35:
           age_dict["30_35"].append(person)
        elif 35 <= person_age < 40:
           age_dict["35_40"].append(person)
        else:
           age_dict["over_40"].append(person)
    return age_dict

一个有用的提示是将calculate_age函数作为属性添加到Person模型中，如:

class Person(TimeStampedModel, Address):
    name = models.CharField(_('nome'), max_length=100)
    birthday = models.DateField(_('data de nascimento'))
    def calculate_age(self):
        today = date.today()
        born = self.birthday
        return today.year - born.year - ((today.month, today.day) < (born.month, born.day))

当你有一个person对象时，你可以这样做

person.calculate_age()

，返回值为年龄