Question

我正在尝试使用用户输入访问代码中的变量。我意识到输入会给我一个字符串而不是变量，但是我不知道如何解决这个问题。我一直收到一条错误：

    AttributeError: 'str' object has no attribute 'email'

这是代码。有什么建议？

    class Person:
    def __init__(self, number, first, last, email):
            self.number =  number
            self.first = first
            self.last = last
            self.email = email



    p1 = Person('1', 'first name', 'last name', 'email address')
    p2 = Person('2', 'first name', 'last name', 'email address')
    p3 = Person('3', 'first name', 'last name', 'email address')
    p5 = Person('5', 'first name', 'last name', 'email address')
    p6 = Person('6', 'first name', 'last name', 'email address')
    p9 = Person('9', 'first name', 'last name', 'email address')
    p10 = Person('10', 'first name', 'last name', 'email address')


    user='p'+raw_input('Please Enter ID Number: ') 


    print(user.email)

Answer 1

使用字典！（虽然不是实现这一目标的唯一方法，但这是正确的方法（至少是imho））

people = dict(
    p1 = Person('1', 'first name', 'last name', 'email address')
    p2 = Person('2', 'first name', 'last name', 'email address')
    p3 = Person('3', 'first name', 'last name', 'email address')
    p5 = Person('5', 'first name', 'last name', 'email address')
    p6 = Person('6', 'first name', 'last name', 'email address')
    p9 = Person('9', 'first name', 'last name', 'email address')
    p10 = Person('10', 'first name', 'last name', 'email address')
)

print people["p"+raw_input("id")]

或使用列表

people = [ Person('1', 'first name', 'last name', 'email address'), Person('1', 'first name', 'last name', 'email address'), Person('1', 'first name', 'last name', 'email address'),...]
print people[int(raw_input("Enter ID:"))]

或更改您的Person班级

class Person:
     people = {}
     def __init__(self,id,first,last,email):
         Person.people[id] = self
         ....
     @classmethod
     def getById(cls,id):
         try:
             return cls.people[id]
         except:
             return None

#then Later

p1 = Person('1', 'first name', 'last name', 'email address')
p2 = Person('2', 'first name', 'last name', 'email address')
p3 = Person('3', 'first name', 'last name', 'email address')
p5 = Person('5', 'first name', 'last name', 'email address')
p6 = Person('6', 'first name', 'last name', 'email address')
p9 = Person('9', 'first name', 'last name', 'email address')
p10 = Person('10', 'first name', 'last name', 'email address')

print Person.getById(raw_input("Enter ID:"))

Answer 2

将Person实例存储在列表或字典中会更好地方式。但是，您可以通过在globals()字典中查找用户输入的变量名称来完成您的工作：

class Person:
    def __init__(self, number, first, last, email):
        self.number =  number
        self.first = first
        self.last = last
        self.email = email

p1 = Person('1', 'first name', 'last name', 'email address1')
p2 = Person('2', 'first name', 'last name', 'email address2')
p3 = Person('3', 'first name', 'last name', 'email address3')
p5 = Person('5', 'first name', 'last name', 'email address5')
p6 = Person('6', 'first name', 'last name', 'email address6')
p9 = Person('9', 'first name', 'last name', 'email address9')
p10 = Person('10', 'first name', 'last name', 'email address10')

user = 'p' + raw_input('Please Enter ID Number: ')
try:
    user = globals()[user]
except KeyError:
    print('ID Number Unknown!')
    raise
print(user.email)

Answer 3

Python将用户解释为字符串“pX”（其中X是输入），而不是变量pX。要解决此问题，您必须将字符串计算为变量。试试print(eval(user).email)。这将评估字符串并返回它所引用的Person对象，然后获取email属性。

使用用户输入访问python中的变量

3 个答案: