local-vs-attr-access.py

import timeit

setup = '''
iter = 1
#iter = 10**6

class Attr:
    def __init__(self):
        self.x = 1
        self._range = range(iter)

    def call(self):
        [self.x for i in self._range]

class Local:
    def __init__(self):
        self.x = 1
        self._range = range(iter)

    def call(self):
        x = self.x
        [x for i in self._range]

a = Attr()
l = Local()
'''

a = timeit.timeit('a.call()', setup, number=1)
l = timeit.timeit('l.call()', setup, number=1)
diff = a - l
print("attr: %f" % a)
print("local: %f" % l)
print("diff: %f" % diff)

# results on my workstation
# for iter=1      diff = between 0 and 3 microseconds
#                        usually 1 microsecond
#                        occasionally -0 and I saw -1 once
# for iter=10**6  diff = 6±1 miliseconds