Pythonic way to assign the parameter into attribute?

Question

The sample codes are like this:

def assign(self, input=None, output=None, param=None, p1=None, p2=None):
    if input:
        self.input = input
    if output:
        self.output = output
    if param:
        self.param = param
    if p1:
        self.p1 = p1
    if p2:
        self.p2 = p2

Though this looks very clear, it suffers if there're 10 parameters for this function. Does anyone have ideas about a more convinient way for this?

Answer 1

you can do something like:

def assign(self,**kwargs):
    for k,v in kwargs.items():
        if v:
           setattr(self,k,v)

This is quite simple and suitable for many situations. If you want to maintain a set of keywords which you'll accept and raise TypeError for the rest:

#python2.7 and newer
def assign(self,allowed_kwargs={'foo','bar','baz'},**kwargs):
    if kwargs.keysview() - allowed_kwargs:
        raise TypeError('useful message here...')
    for k in allowed_kwargs:
        setattr(self,k,kwargs[k])

This is somewhat inspect-able as well since the user will see the set of allowed kwargs.