use Jython

Hoge.py

#!/usr/bin/env jython                                                                                                                                                                                                                 
# -*- coding: utf-8 -*-                                                                                                                                                                                                               

class Fuga(object):

    def __init__(self, color, weight):
        self.color = color
        self.weight = weight


if __name__ == '__main__':
    lst = [Fuga('blue', 10), Fuga('red', 30), Fuga('blue', 50)]

    weight = reduce(lambda acc, e: acc + e,
                    map(lambda it: it.weight,
                        filter(lambda it: it.color == 'blue', lst)),
                    0)

    print(weight)