getattr() 获取对象的属性

内置函数 getattr()，Python 官方文档描述如下：

help(getattr)

Help on built-in function getattr in module builtins:

getattr(...)
    getattr(object, name[, default]) -> value
    
    Get a named attribute from an object; getattr(x, 'y') is equivalent to x.y.
    When a default argument is given, it is returned when the attribute doesn't
    exist; without it, an exception is raised in that case.

返回对象给定的属性名指向的值。name 必须是字符串。如果该字符串是对象的属性名称之一，则返回该属性的值。例如，getattr(x, 'y') 等同于 x.y。如果指定的属性不存在，且提供了 default 值，则返回它，否则触发 AttributeError。

getattr(1,'imag')

getattr(1,'bool',True)

True

getattr(1,'bool')

---------------------------------------------------------------------------

AttributeError                            Traceback (most recent call last)

<ipython-input-6-524bb2b35e58> in <module>
----> 1 getattr(1,'bool')


AttributeError: 'int' object has no attribute 'bool'

class A:
    y = 1
x = A()
x.y

getattr(x,'y')