python test __setattr_()

class_test3.py

# test: set of class object
class part(object):
    def __init__(self, name='unknown', val=100, flag=False):
        self.name = name
        self.val = val
        self.flag = flag
    def __setattr__(self, name, value):
        if name=='name':
            # if isinstance(value, str): self.__dict__[name] = value
            if isinstance(value, str): object.__setattr__(self, name, value)
        elif name=='flag':
            # if isinstance(value, bool): self.__dict__[name] = value
            if isinstance(value, bool): object.__setattr__(self, name, value)
        else:
            # self.__dict__[name] = value
            object.__setattr__(self, name, value)

# test
p = part()
p.name = None
p.val = 'aa'
p.flag = None
print p.__dict__

p.name = 'a'
p.val = 2
p.flag = True
print p.__dict__