The same method for class and instance

Question

I have class Books and method select in it. Also there is an instance of that class called book. I want to be able to do both Bo

Answer 1

You could use a descriptor:

class Select(object):
    def __get__(self,obj,objtype):
        x=objtype if obj is None else obj
        def select(where):
            print(x,where)
        return select
class Books(object):
    select=Select()

book = Books()
Books.select(where='asdf')
book.select(where='asdf')

yields

<class '__main__.Books'> asdf
<__main__.Books object at 0xb7696dec> asdf

Answer 2

Solution using a descriptor and a decorator:

class class_or_instance_method():
    def __init__(self, method):
        self.method = method

    def __get__(self, obj, objtype):
        x = obj or objtype
        def wrapped(*args, **kwargs):
            return self.method(x, *args, **kwargs)
        return wrapped        

class Books():
    @class_or_instance_method
    def select(obj, where):
        print(obj, where)


book = Books()
Books.select(where='asdf')
book.select(where='asdf')

Result:

<class '__main__.Books'> asdf
<__main__.Books object at 0x2695890> asdf

Answer 3

Just an example I founded on http://code.activestate.com/recipes/52304-static-methods-aka-class-methods-in-python/

You create a little wrapper:

class Callable:
    def __init__(self, anycallable):
        self.__call__ = anycallable

And then defines your class and a class variable inside it.

class Class2:
    def static2(name):
        print "Hi there",name
    static2 = Callable(static2)

# now, a call such as:
Class2.static2("Peter")
# works just fine, and as-expected