#!/usr/bin/env python3

from operator import itemgetter
from timeit import default_timer as timer

def single_pass_data():
    return [
        {
            'col0': i // (8 ** 0) % 8,
            'col1': i // (8 ** 1) % 8,
            'col2': i // (8 ** 2) % 8,
            'col3': i // (8 ** 3) % 8,
            'col4': i // (8 ** 4) % 8,
            'col5': i // (8 ** 5) % 8,
            'col6': i // (8 ** 6) % 8,
            'col7': i,
        }
        for i in range(8 ** 8)
    ]

def multi_pass_data():
    return [
        {
            'col0': i,
            'col1': 0,
            'col2': 0,
            'col3': 0,
            'col4': 0,
            'col5': 0,
            'col6': 0,
            'col7': 0,
        }
        for i in range(8 ** 8)
    ]

def single_pass_func(data):
    data.sort(key=lambda x: (
        itemgetter('col7')(x),
        itemgetter('col6')(x),
        itemgetter('col5')(x),
        itemgetter('col4')(x),
        itemgetter('col3')(x),
        itemgetter('col2')(x),
        itemgetter('col1')(x),
        itemgetter('col0')(x),
    ))

def multi_pass_func(data):
    data.sort(key=itemgetter('col0'))
    data.sort(key=itemgetter('col1'))
    data.sort(key=itemgetter('col2'))
    data.sort(key=itemgetter('col3'))
    data.sort(key=itemgetter('col4'))
    data.sort(key=itemgetter('col5'))
    data.sort(key=itemgetter('col6'))
    data.sort(key=itemgetter('col7'))

if __name__ == '__main__':
    for data in (single_pass_data, multi_pass_data):
        _data = data()
        for func in (single_pass_func, multi_pass_func):
            t = timer()
            func(_data)
            print('{}({})={}'.format(func.__name__, data.__name__, timer() - t))