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allendowney
GitHub Repository: allendowney/cpython
 Path: blob/main/Tools/scripts/var_access_benchmark.py
12 views
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'Show relative speeds of local, nonlocal, global, and built-in access.'

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# Please leave this code so that it runs under older versions of

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# Python 3 (no f-strings).  That will allow benchmarking for

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# cross-version comparisons.  To run the benchmark on Python 2,

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# comment-out the nonlocal reads and writes.

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from collections import deque, namedtuple

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trials = [None] * 500

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steps_per_trial = 25

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class A(object):

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    def m(self):

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        pass

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class B(object):

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    __slots__ = 'x'

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    def __init__(self, x):

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        self.x = x

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class C(object):

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    def __init__(self, x):

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        self.x = x

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def read_local(trials=trials):

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    v_local = 1

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    for t in trials:

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        v_local;    v_local;    v_local;    v_local;    v_local

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        v_local;    v_local;    v_local;    v_local;    v_local

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        v_local;    v_local;    v_local;    v_local;    v_local

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        v_local;    v_local;    v_local;    v_local;    v_local

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        v_local;    v_local;    v_local;    v_local;    v_local

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def make_nonlocal_reader():

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    v_nonlocal = 1

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    def inner(trials=trials):

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        for t in trials:

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            v_nonlocal; v_nonlocal; v_nonlocal; v_nonlocal; v_nonlocal

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            v_nonlocal; v_nonlocal; v_nonlocal; v_nonlocal; v_nonlocal

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            v_nonlocal; v_nonlocal; v_nonlocal; v_nonlocal; v_nonlocal

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            v_nonlocal; v_nonlocal; v_nonlocal; v_nonlocal; v_nonlocal

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            v_nonlocal; v_nonlocal; v_nonlocal; v_nonlocal; v_nonlocal

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    inner.__name__ = 'read_nonlocal'

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    return inner

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read_nonlocal = make_nonlocal_reader()

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v_global = 1

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def read_global(trials=trials):

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    for t in trials:

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        v_global; v_global; v_global; v_global; v_global

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        v_global; v_global; v_global; v_global; v_global

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        v_global; v_global; v_global; v_global; v_global

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        v_global; v_global; v_global; v_global; v_global

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        v_global; v_global; v_global; v_global; v_global

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def read_builtin(trials=trials):

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    for t in trials:

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        oct; oct; oct; oct; oct

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        oct; oct; oct; oct; oct

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        oct; oct; oct; oct; oct

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        oct; oct; oct; oct; oct

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        oct; oct; oct; oct; oct

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def read_classvar_from_class(trials=trials, A=A):

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    A.x = 1

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    for t in trials:

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        A.x;    A.x;    A.x;    A.x;    A.x

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        A.x;    A.x;    A.x;    A.x;    A.x

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        A.x;    A.x;    A.x;    A.x;    A.x

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        A.x;    A.x;    A.x;    A.x;    A.x

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        A.x;    A.x;    A.x;    A.x;    A.x

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def read_classvar_from_instance(trials=trials, A=A):

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    A.x = 1

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    a = A()

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    for t in trials:

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        a.x;    a.x;    a.x;    a.x;    a.x

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        a.x;    a.x;    a.x;    a.x;    a.x

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        a.x;    a.x;    a.x;    a.x;    a.x

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        a.x;    a.x;    a.x;    a.x;    a.x

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        a.x;    a.x;    a.x;    a.x;    a.x

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def read_instancevar(trials=trials, a=C(1)):

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    for t in trials:

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        a.x;    a.x;    a.x;    a.x;    a.x

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        a.x;    a.x;    a.x;    a.x;    a.x

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        a.x;    a.x;    a.x;    a.x;    a.x

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        a.x;    a.x;    a.x;    a.x;    a.x

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        a.x;    a.x;    a.x;    a.x;    a.x

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def read_instancevar_slots(trials=trials, a=B(1)):

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    for t in trials:

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        a.x;    a.x;    a.x;    a.x;    a.x

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        a.x;    a.x;    a.x;    a.x;    a.x

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        a.x;    a.x;    a.x;    a.x;    a.x

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        a.x;    a.x;    a.x;    a.x;    a.x

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        a.x;    a.x;    a.x;    a.x;    a.x

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def read_namedtuple(trials=trials, D=namedtuple('D', ['x'])):

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    a = D(1)

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    for t in trials:

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        a.x;    a.x;    a.x;    a.x;    a.x

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        a.x;    a.x;    a.x;    a.x;    a.x

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        a.x;    a.x;    a.x;    a.x;    a.x

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        a.x;    a.x;    a.x;    a.x;    a.x

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        a.x;    a.x;    a.x;    a.x;    a.x

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def read_boundmethod(trials=trials, a=A()):

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    for t in trials:

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        a.m;    a.m;    a.m;    a.m;    a.m

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        a.m;    a.m;    a.m;    a.m;    a.m

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        a.m;    a.m;    a.m;    a.m;    a.m

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        a.m;    a.m;    a.m;    a.m;    a.m

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        a.m;    a.m;    a.m;    a.m;    a.m

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def write_local(trials=trials):

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    v_local = 1

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    for t in trials:

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        v_local = 1; v_local = 1; v_local = 1; v_local = 1; v_local = 1

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        v_local = 1; v_local = 1; v_local = 1; v_local = 1; v_local = 1

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        v_local = 1; v_local = 1; v_local = 1; v_local = 1; v_local = 1

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        v_local = 1; v_local = 1; v_local = 1; v_local = 1; v_local = 1

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        v_local = 1; v_local = 1; v_local = 1; v_local = 1; v_local = 1

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def make_nonlocal_writer():

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    v_nonlocal = 1

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    def inner(trials=trials):

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        nonlocal v_nonlocal

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        for t in trials:

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            v_nonlocal = 1; v_nonlocal = 1; v_nonlocal = 1; v_nonlocal = 1; v_nonlocal = 1

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            v_nonlocal = 1; v_nonlocal = 1; v_nonlocal = 1; v_nonlocal = 1; v_nonlocal = 1

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            v_nonlocal = 1; v_nonlocal = 1; v_nonlocal = 1; v_nonlocal = 1; v_nonlocal = 1

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            v_nonlocal = 1; v_nonlocal = 1; v_nonlocal = 1; v_nonlocal = 1; v_nonlocal = 1

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            v_nonlocal = 1; v_nonlocal = 1; v_nonlocal = 1; v_nonlocal = 1; v_nonlocal = 1

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    inner.__name__ = 'write_nonlocal'

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    return inner

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write_nonlocal = make_nonlocal_writer()

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def write_global(trials=trials):

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    global v_global

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    for t in trials:

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        v_global = 1; v_global = 1; v_global = 1; v_global = 1; v_global = 1

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        v_global = 1; v_global = 1; v_global = 1; v_global = 1; v_global = 1

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        v_global = 1; v_global = 1; v_global = 1; v_global = 1; v_global = 1

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        v_global = 1; v_global = 1; v_global = 1; v_global = 1; v_global = 1

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        v_global = 1; v_global = 1; v_global = 1; v_global = 1; v_global = 1

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def write_classvar(trials=trials, A=A):

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    for t in trials:

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        A.x = 1;    A.x = 1;    A.x = 1;    A.x = 1;    A.x = 1

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        A.x = 1;    A.x = 1;    A.x = 1;    A.x = 1;    A.x = 1

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        A.x = 1;    A.x = 1;    A.x = 1;    A.x = 1;    A.x = 1

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        A.x = 1;    A.x = 1;    A.x = 1;    A.x = 1;    A.x = 1

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        A.x = 1;    A.x = 1;    A.x = 1;    A.x = 1;    A.x = 1

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def write_instancevar(trials=trials, a=C(1)):

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    for t in trials:

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        a.x = 1;    a.x = 1;    a.x = 1;    a.x = 1;    a.x = 1

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        a.x = 1;    a.x = 1;    a.x = 1;    a.x = 1;    a.x = 1

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        a.x = 1;    a.x = 1;    a.x = 1;    a.x = 1;    a.x = 1

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        a.x = 1;    a.x = 1;    a.x = 1;    a.x = 1;    a.x = 1

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        a.x = 1;    a.x = 1;    a.x = 1;    a.x = 1;    a.x = 1

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def write_instancevar_slots(trials=trials, a=B(1)):

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    for t in trials:

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        a.x = 1;    a.x = 1;    a.x = 1;    a.x = 1;    a.x = 1

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        a.x = 1;    a.x = 1;    a.x = 1;    a.x = 1;    a.x = 1

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        a.x = 1;    a.x = 1;    a.x = 1;    a.x = 1;    a.x = 1

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        a.x = 1;    a.x = 1;    a.x = 1;    a.x = 1;    a.x = 1

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        a.x = 1;    a.x = 1;    a.x = 1;    a.x = 1;    a.x = 1

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def read_list(trials=trials, a=[1]):

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    for t in trials:

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        a[0];   a[0];   a[0];   a[0];   a[0]

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        a[0];   a[0];   a[0];   a[0];   a[0]

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        a[0];   a[0];   a[0];   a[0];   a[0]

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        a[0];   a[0];   a[0];   a[0];   a[0]

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        a[0];   a[0];   a[0];   a[0];   a[0]

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def read_deque(trials=trials, a=deque([1])):

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    for t in trials:

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        a[0];   a[0];   a[0];   a[0];   a[0]

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        a[0];   a[0];   a[0];   a[0];   a[0]

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        a[0];   a[0];   a[0];   a[0];   a[0]

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        a[0];   a[0];   a[0];   a[0];   a[0]

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        a[0];   a[0];   a[0];   a[0];   a[0]

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def read_dict(trials=trials, a={0: 1}):

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    for t in trials:

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        a[0];   a[0];   a[0];   a[0];   a[0]

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        a[0];   a[0];   a[0];   a[0];   a[0]

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        a[0];   a[0];   a[0];   a[0];   a[0]

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        a[0];   a[0];   a[0];   a[0];   a[0]

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        a[0];   a[0];   a[0];   a[0];   a[0]

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def read_strdict(trials=trials, a={'key': 1}):

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    for t in trials:

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        a['key'];   a['key'];   a['key'];   a['key'];   a['key']

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        a['key'];   a['key'];   a['key'];   a['key'];   a['key']

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        a['key'];   a['key'];   a['key'];   a['key'];   a['key']

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        a['key'];   a['key'];   a['key'];   a['key'];   a['key']

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        a['key'];   a['key'];   a['key'];   a['key'];   a['key']

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def list_append_pop(trials=trials, a=[1]):

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    ap, pop = a.append, a.pop

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    for t in trials:

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        ap(1); pop(); ap(1); pop(); ap(1); pop(); ap(1); pop(); ap(1); pop()

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        ap(1); pop(); ap(1); pop(); ap(1); pop(); ap(1); pop(); ap(1); pop()

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        ap(1); pop(); ap(1); pop(); ap(1); pop(); ap(1); pop(); ap(1); pop()

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        ap(1); pop(); ap(1); pop(); ap(1); pop(); ap(1); pop(); ap(1); pop()

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        ap(1); pop(); ap(1); pop(); ap(1); pop(); ap(1); pop(); ap(1); pop()

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def deque_append_pop(trials=trials, a=deque([1])):

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    ap, pop = a.append, a.pop

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    for t in trials:

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        ap(1); pop(); ap(1); pop(); ap(1); pop(); ap(1); pop(); ap(1); pop()

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        ap(1); pop(); ap(1); pop(); ap(1); pop(); ap(1); pop(); ap(1); pop()

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        ap(1); pop(); ap(1); pop(); ap(1); pop(); ap(1); pop(); ap(1); pop()

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        ap(1); pop(); ap(1); pop(); ap(1); pop(); ap(1); pop(); ap(1); pop()

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        ap(1); pop(); ap(1); pop(); ap(1); pop(); ap(1); pop(); ap(1); pop()

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def deque_append_popleft(trials=trials, a=deque([1])):

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    ap, pop = a.append, a.popleft

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    for t in trials:

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        ap(1); pop(); ap(1); pop(); ap(1); pop(); ap(1); pop(); ap(1); pop();

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        ap(1); pop(); ap(1); pop(); ap(1); pop(); ap(1); pop(); ap(1); pop();

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        ap(1); pop(); ap(1); pop(); ap(1); pop(); ap(1); pop(); ap(1); pop();

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        ap(1); pop(); ap(1); pop(); ap(1); pop(); ap(1); pop(); ap(1); pop();

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        ap(1); pop(); ap(1); pop(); ap(1); pop(); ap(1); pop(); ap(1); pop();

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def write_list(trials=trials, a=[1]):

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    for t in trials:

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        a[0]=1; a[0]=1; a[0]=1; a[0]=1; a[0]=1

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        a[0]=1; a[0]=1; a[0]=1; a[0]=1; a[0]=1

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        a[0]=1; a[0]=1; a[0]=1; a[0]=1; a[0]=1

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        a[0]=1; a[0]=1; a[0]=1; a[0]=1; a[0]=1

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        a[0]=1; a[0]=1; a[0]=1; a[0]=1; a[0]=1

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def write_deque(trials=trials, a=deque([1])):

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    for t in trials:

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        a[0]=1; a[0]=1; a[0]=1; a[0]=1; a[0]=1

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        a[0]=1; a[0]=1; a[0]=1; a[0]=1; a[0]=1

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        a[0]=1; a[0]=1; a[0]=1; a[0]=1; a[0]=1

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        a[0]=1; a[0]=1; a[0]=1; a[0]=1; a[0]=1

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        a[0]=1; a[0]=1; a[0]=1; a[0]=1; a[0]=1

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def write_dict(trials=trials, a={0: 1}):

251
    for t in trials:

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        a[0]=1; a[0]=1; a[0]=1; a[0]=1; a[0]=1

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        a[0]=1; a[0]=1; a[0]=1; a[0]=1; a[0]=1

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        a[0]=1; a[0]=1; a[0]=1; a[0]=1; a[0]=1

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        a[0]=1; a[0]=1; a[0]=1; a[0]=1; a[0]=1

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        a[0]=1; a[0]=1; a[0]=1; a[0]=1; a[0]=1

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def write_strdict(trials=trials, a={'key': 1}):

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    for t in trials:

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        a['key']=1; a['key']=1; a['key']=1; a['key']=1; a['key']=1

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        a['key']=1; a['key']=1; a['key']=1; a['key']=1; a['key']=1

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        a['key']=1; a['key']=1; a['key']=1; a['key']=1; a['key']=1

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        a['key']=1; a['key']=1; a['key']=1; a['key']=1; a['key']=1

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        a['key']=1; a['key']=1; a['key']=1; a['key']=1; a['key']=1

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def loop_overhead(trials=trials):

267
    for t in trials:

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        pass

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if __name__=='__main__':

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273
    from timeit import Timer

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    for f in [

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            'Variable and attribute read access:',

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            read_local, read_nonlocal, read_global, read_builtin,

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            read_classvar_from_class, read_classvar_from_instance,

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            read_instancevar, read_instancevar_slots,

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            read_namedtuple, read_boundmethod,

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            '\nVariable and attribute write access:',

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            write_local, write_nonlocal, write_global,

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            write_classvar, write_instancevar, write_instancevar_slots,

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            '\nData structure read access:',

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            read_list, read_deque, read_dict, read_strdict,

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            '\nData structure write access:',

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            write_list, write_deque, write_dict, write_strdict,

288
            '\nStack (or queue) operations:',

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            list_append_pop, deque_append_pop, deque_append_popleft,

290
            '\nTiming loop overhead:',

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            loop_overhead]:

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        if isinstance(f, str):

293
            print(f)

294
            continue

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        timing = min(Timer(f).repeat(7, 1000))

296
        timing *= 1000000 / (len(trials) * steps_per_trial)

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        print('{:6.1f} ns\t{}'.format(timing, f.__name__))

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