python - 调用一个字符串类型的类属性

Question

这是我的类实现

class A:

    def __init__(self,a,b):
        self.result = None
        self.a = a
        self.b = b
        self.add()

    def add(self):
        self.result = self.a+self.b
        return

我的类(class) A 将结果作为一个属性。我想访问类属性，即；通过从字典中读取结果字符串得到结果。下面是我尝试过的实现。

x = 'result' # I will get from other source
obj = A(1,2)
obj.x # Here x = result and the result is the actual class attribute

Error:
AttributeError: A instance has no attribute 'x'

谁能告诉我如何通过将字符串转换为对象来访问类属性？

Answer 1

使用 getattr

getattr 将完全按照您的要求进行操作。

class A:

    def __init__(self,a,b):
        self.result = ''
        self.a = a
        self.b = b
        self.add()

    def add(self):
        self.result = self.a+self.b
        return

x = 'result' # I will get from other source
obj = A(1,2)
obj.add() #this was missing before thus obj.result would've been 0
print getattr(obj, x) # Here x = result and the result is the actual class attribute