Question

For code:

class a(object):
    a='aaa'
b=a()
print hasattr(a,'a')
print hasattr(b,'a')

who can be called by hasattr except ‘class somebody’?

Thanks!

Answer 1

You can call hasattr with any object as the first argument (and any string as the second argument): it just returns False if that object does not have an attribute by that name (“having” an attribute of course includes possibly inheriting or synthesizing it; hasattr(x,'y') is True if and only if accessing x.y would not raise an exception — that’s how it works internally: it tries getattr and catches the exception if any).