Based on https://docs.python.org/release/2.6.6/faq/programming.html#my-program-is-too-slow-how-do-i-speed-it-up
Python 2
$ ipython
Python 2.7.12 (default, Sep 11 2016, 21:48:40)
Type "copyright", "credits" or "license" for more information.
In [21]: from timeit import timeit
In [22]: setup1 = "a = {1: 'a'}"
In [23]: setup2 = """\
...: a = {1: 'a'}
...: a_get = a.get"""
In [24]: stmt1 = """\
...: for i in range(1000000):
...: a.get(1, 0)
...: """
In [25]: stmt2 = """\
...: for i in range(1000000):
...: a_get(1, 0)
...: """
In [26]: timeit(stmt1, setup1, number=1000)
Out[26]: 125.40199017524719
In [27]: timeit(stmt2, setup2, number=1000)
Out[27]: 87.49684882164001
Python 3
$ ipython3
Python 3.4.5 (default, Sep 11 2016, 21:45:49)
Type "copyright", "credits" or "license" for more information.
In [1]: setup1 = "a = {1: 'a'}"
In [2]: setup2 = """\
...: a = {1: 'a'}
...: a_get = a.get"""
In [3]: stmt1 = """\
...: for i in range(1000000):
...: a.get(1, 0)
...: """
In [4]: stmt2 = """\
...: for i in range(1000000):
...: a_get(1, 0)
...: """
In [6]: from timeit import timeit
In [7]: timeit(stmt1, setup1, number=1000)
Out[7]: 121.0638571190002
In [8]: timeit(stmt2, setup2, number=1000)
Out[8]: 85.85463693700058
Based on https://docs.python.org/release/2.6.6/faq/programming.html#why-does-22-10-return-3
$ ipython
Python 2.7.12 (default, Sep 11 2016, 21:48:40)
Type "copyright", "credits" or "license" for more information.
IPython 5.1.0 -- An enhanced Interactive Python.
? -> Introduction and overview of IPython's features.
%quickref -> Quick reference.
help -> Python's own help system.
object? -> Details about 'object', use 'object??' for extra details.
In [1]: 10 / 3
Out[1]: 3
In [2]: 10 // 3
Out[2]: 3
In [3]: from __future__ import division
In [4]: 10 / 3
Out[4]: 3.3333333333333335
In [5]: 10 // 3
Out[5]: 3