读取判读python对象所含有的属性方法是什么,判读python,怎么在使用前判断 Pyt


怎么在使用前判断 Python 对象是否包含某个属性或者某个方法?

class FooClass:    passk = FooClass()k.someAtt = 2k.att

输出:

Traceback (most recent call last):  File "Untitled.py", line 6, in <module>    k.attAttributeError: FooClass instance has no attribute 'att'

http://stackoverflow.com/questions/3681272/can-i-get-a-reference-to-a-python-property
http://stackoverflow.com/questions/191010/how-to-get-a-complete-list-of-objects-methods-and-attributes

dir(FooClass)

方法一:通过异常捕捉来实现逻辑

class FooClass:passk = FooClass()try:    #do some thing you need    print k.attexcept AttributeError as e:    #error: has not attribute    pass 

方法二:调用hasattr方法

hasattr(object, name)
说明:判断对象object是否包含名为name的特性(hasattr是通过调用getattr(ojbect, name)是否抛出异常来实现的)。
参数object:对象。
参数name:特性名称。

>>> hasattr(list, 'append')True>>> hasattr(list, 'add')False

方法三:使用dir方法

objlist = dir(k)if 'att' in objlist:    #do some thing you need    print k.attelse:    #error: has not attribute    pass

另外, 这种问题可以使用google搜索下,善用google

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