listplay.py

class Order(object):
    reverse = False

    def __init__(self, attrs, reverse=False):
        self.attrs = attrs
        self.reverse = reverse
        
    def __call__(self, l):
        return sorted(l, 
                      key=lambda el: [getattr(el, name) for name in self.attrs],
                      reverse=self.reverse)

   
def order_by(*args):
    return Order(args)


def reverse_order_by(*args):
    return Order(args, reverse=True)


class WhereEq(dict):
    
    def __call__(self, l):
        for item in l:
            for name in self:
                if getattr(item, name) != self.get(name):
                    break
            else:
                # fallthrough incase no break
                yield item


def where_eq(**kwargs):
    return WhereEq(kwargs)


def select_many(l, *set_modifiers):
    for setmod in set_modifiers:
        l = setmod(l)

    return list(l)

#
# Example
#

class Cls(object):
    name = None
    age = None

    def __init__(self, name, age):
        self.name = name
        self.age = age

    def __repr__(self):
        return 'Cls(name=%r, age=%r)' % (self.name, self.age)


l = [Cls('Kalle', 5), Cls('Anna', 5), Cls('Sven', 53)]

print select_many(l, order_by('name', 'age'), where_eq(age=5)) # [Cls(name='Anna', age=5), Cls(name='Kalle', age=5)]
print select_many(l, where_eq(age=5), reverse_order_by('name', 'age')) # [Cls(name='Kalle', age=5), Cls(name='Anna', age=5)]