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Ole Lukøje
Asked:2020-11-02 02:37:45 +0000 UTC2020-11-02 02:37:45 +0000 UTC

类实例的标识。Python

  • 772

是否可以创建一个类的多个实例，然后通过某些标识符来引用它们，而不是将这些实例添加到字典或列表中？

好吧，事情就是这样： 

from csv import DictReader

sched_file = open('schedule.csv')
schedule = DictReader(sched_file)


class Day:
    def __init__(self, w_day: dict):
        self.week_day = w_day['week_day']
        self.name = w_day['week_day_name']


days = {item['week_day']: Day(item) for item in schedule}

print(days['3'].name)

# Wednesday

有没有其他方法可以解决这个问题？原则上， “否”
的答案 适合我，我会冷静下来忘记这个话题））

schedule.csv

"week_day","week_day_name","week_day_alt_name","les1","les2","les3","les4","les5","les6","les7","les8"
"1","Monday","Понедельник","Геометрия","Физкультура","Немецкий язык","Физика","Биология","Основы здоровья","Зарубежная литература",""
"2","Tuesday","Вторник","Химия","Английский язык","Украинский язык","Алгебра","Украинская литература","Информатика","Труды",""
"3","Wednesday","Среда","Немецкий язык","Мистецтво","Алгебра","Физика","Правознавство","География","Всемирная история","Физкультура"
"4","Thursday","Четверг","Английский язык","Алгебра","Химия","Зарубежная литература","Информатика","Всемирная история","Биология",""
"5","Friday","Пятница","Геометрия","Физкультура","Физика","Английский язык","Украинский язык","География","Украинская литература","Виховна година"
"6","Saturday","Суббота","","","","","","","",""
"7","Sunday","Воскресенье","","","","","","","",""
python

3 个回答

  1. 您可以生成变量，但这是一种奇怪的方式 - 将它们设为常量更容易。

    ...

class Day:
    def __init__(self, w_day: dict):
        self.week_day = w_day['week_day']
        self.name = w_day['week_day_name']


for item in schedule:
    day = Day(item)

    var = 'week_day_' + item['week_day']
    globals()[var] = day

    var = 'week_day_' + item['week_day_name']
    globals()[var] = day


print(week_day_3.name)          # Wednesday
print(week_day_Wednesday.name)  # Wednesday
print(week_day_Sunday.name)     # Sunday
    • 2

  2. 您可以尝试使用类字段来执行以下操作：

    ...

class Day:
    def __init__(self, w_day: dict):
        self.week_day = w_day['week_day']
        self.name = w_day['week_day_name']

        setattr(Day, 'WEEK_DAY_' + self.week_day, self)
        setattr(Day, 'WEEK_DAY_' + self.name, self)


for item in schedule:
    day = Day(item)


print(Day.WEEK_DAY_3.name)          # Wednesday
print(Day.WEEK_DAY_Wednesday.name)  # Wednesday
print(Day.WEEK_DAY_Sunday.name)     # Sunday
    • 1
  3. Best Answer

    略简化版不读csv

    sched = (('1', 'Monday'), ('2', 'Tuesday'))


class Day:
    def __init__(self, row):
        self.id = int(row[0])
        self.name = row[1]

    def __str__(self):
        return '<{}: {}>'.format(self.id, self.name)


class Schedule:
    def __init__(self, lst):
        self.items = {int(row[0]): Day(row) for row in lst}

    def __getitem__(self, index):
        return self.items[index]

    def __call__(self, name):
        for _, item in self.items.items():
            if item.name == name:
                return item
        raise AttributeError('Wrong argument')

    def __getattr__(self, name):
        return self(name)


schedule = Schedule(sched)
print schedule[1]
print schedule('Tuesday')
print schedule.Tuesday

    D:\Python\python.exe D:/PycharmProjects/tl/aa.py
<1: Monday>
<2: Tuesday>
<2: Tuesday>


Process finished with exit code 0

    PS对不起第二条蟒蛇

    • 1

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