optimize

optimize.py

# Old implementation.  Can you spot the optimization?
predicates = [lambda x: x.is_rad(), lambda x: x.is_cool(), lambda x: x.is_baller()]
all_products = Product.objects.all()
products = reduce(
    lambda filtered_so_far, predicate: filter(predicate, filtered_so_far),
    predicates,
    all_products
)

# New implementation
def and_combinate(f,g):
    return lambda x: f(x) and g(x)

predicates = [lambda x: x.is_rad(), lambda x: x.is_cool(), lambda x: x.is_baller()]
all_products = Product.objects.all()
combofilter = reduce(and_combinate, predicates)
products = filter(combofilter, all_products)