如何创建一个从其参数生成类实例的函数

Question

我是一个python newbie，我正在尝试创建一个函数，该函数使用该函数作为实例的属性的参数返回三个类之一的实例。

class User:
    def __init__(self, nick, full_name, reg_date, age, role):
        self.nick = nick
        self.full_name = full_name 
        self.reg_date = reg_date
        self.age = age
        self.role = role

class Staff(User):
    def __init__(self, nick, full_name, reg_date, age, role):
        super().__init__(nick, full_name, reg_date, age, role)


class Adult(Staff):
    def __init__(self, nick, full_name, reg_date, age, role):
        super().__init__(nick, full_name, reg_date, age, role)

class Young(Adult):
    def __init__(self,nick, full_name, reg_date, age, role):
        super().__init__(full_name, nick, reg_date, age, role)



def sign_up(nick, full_name, reg_date, age, role):
    nick = (input('Choose a nickname: '))
    full_name = (input('Please, introduce your name: '))
    reg_date = str(date.today())
    age = (input('Please, introduce your age: '))
    role = (input('Please, introduce your role (Staff, Adult or Young)'))
    valid_roles = ['Staff', 'Adult', 'Young']
    exec('nick = role(full_name, reg_date, age, role)

我的目标是，当您在函数中运行符号时，用户将用户引入“ nick”参数的值将是实例名称，角色instancem的类别，而其他参数可作为实例。

例如：

sign_in('nick1', 'John Doe', reg_date, 38, 'Staff')

应该导致这样做：

nick1 = Staff(full_name, reg_date, age)

是我在堆栈溢出中的第一个问题，希望我能清楚地解释自己。谢谢。

Answer 1

不要任意做变量。改用词典之类的内容。

class User:
    def __init__(self, nick, full_name, reg_date, age, role):
        self.nick = nick
        self.full_name = full_name 
        self.reg_date = reg_date
        self.age = age
        self.role = role

class Staff(User):
    pass

class Adult(Staff):
    pass

class Young(Adult):
    pass

def sign_up(nick, full_name, reg_date, age, role):
    user = {}
    if role == 'Staff':
        user[nick] = Staff(nick, full_name, reg_date, age, role)
    elif role == 'Adult':
        user[nick] = Adult(nick, full_name, reg_date, age, role)
    elif role == 'Young':
        user[nick] = Young(nick, full_name, reg_date, age, role)
    return user

users = {}

users |= sign_up('nick1', 'John Doe', 'today', 38, 'Staff')
users |= sign_up('nick2', 'Jane Doe', 'yesterday', 40, 'Adult')
print(users)

输出：

{'nick1': <__main__.Staff object at 0x1009d2c80>,
 'nick2': <__main__.Adult object at 0x100ae1b10>}