How to return a class instance in member function of a class?

Question

I want to return a class instance in member function of a class, my code is:

class MyClass(object):
    def __init__(self, *args, **kwargs):
        [snippet]

    def func(self, *args, **kwargs):
        [snippet]
        return class_instnace_of_MyClass

if __name__ == '__main__':
    obj = MyClass(...)
    newobj = obj.func(...)  # type(newobj) is MyClass

I think I can call __init__() in func(), and return a new instance of MyClass, but I don't think it is a Pythonic way to do so. How should I do that? Thank you!

Answer 1

I feel like you should use the @classmethod decorator for this, if I'm reading your question right. Something like:

class myClass(object):

    def __int__(name):
        self.name = name

    @classmethod
    def from_fancy(cls, name):
        #do something with name, maybe make it 
        #lowercase or something...
        return cls(name)

For example, in the pandas package you can create a DateFrame object by doing things like pandas.DataFrame.from_csv(...) or pandas.DataFrame.from_json(...). Each of those are class methods which return a DataFrame object, created with different initial data sets (csv text file or a JSON text file).

For instance, you would call it like:

my_new_object = myClass.from_fancy("hello world")

There's a good thread on @classmethod here