Benchmark of lazy properties in python

gistfile1.txt

from __future__ import print_function
import timeit

t1 = """
class Test():
    _bar = None

    @property
    def bar(self):
        if self._bar is not None:
            return self._bar
        self._bar = 42
        return self._bar
test = Test()
"""

t2 = """
class Test():
    @property
    def bar(self):
        self.bar = 42
        return 42
test = Test()
"""

t3 = """
class LazyProperty(object):

    def __init__(self, func):
        self._func = func
        self.__name__ = func.__name__
        self.__doc__ = func.__doc__

    def __get__(self, obj, klass=None):
        if obj is None: return None
        result = obj.__dict__[self.__name__] = self._func(obj)
        return result

class Foo(object):
    @LazyProperty
    def bar(self):
        return 42
test = Foo()
"""

tests = (t1, t2, t3)

print("Calculation and one lookup")
for t in tests:
    timer = timeit.Timer("test.bar; test.bar", t)
    try:
        print("%.2f usec/pass" % (1000000 * timer.timeit(number=100000)/100000))
    except:
        timer.print_exc()

print("One post calculation lookup")
for t in tests:
    timer = timeit.Timer("test.bar", t + "\ntest.bar")
    try:
        print("%.2f usec/pass" % (1000000 * timer.timeit(number=100000)/100000))
    except:
        timer.print_exc()