________________________________ > From: Vipul Sharma <vipul.sharm...@gmail.com> >To: tutor@python.org >Sent: Saturday, April 19, 2014 10:48 PM >Subject: [Tutor] equality check difference > > > >Hello, > > >Suppose we want some block of code to be executed when both 'a' and 'b' are >equal to say 5. Then we can write like : > > >if a == 5 and b == 5: > # do something > > >But a few days ago, I just involuntarily wrote a similar condition check as : > > >if a == b and b == 5: > # do something > > >which made me think, is there any difference between the two ? > > >Is there any difference, any difference in the process of evaluation or >execution ? and also which one is the better ? > > >I think this is a general programming question and not specifically for python. > > >P.S. : Newbie here :)
I used timeit and it does not seem to make a big difference. The dis module could help give insight what Python is doing behind the scenes (I am not so familiar with that module). $ipython Python 2.7.3 (default, Feb 27 2014, 19:39:10) Type "copyright", "credits" or "license" for more information. IPython 0.13.1 -- An enhanced Interactive Python. In [1]: a, b = 1, 2 In [2]: %timeit if a == 5 and b == 5: pass 1000000 loops, best of 3: 1.1 us per loop In [3]: %timeit if a == b and b == 5: pass 1000000 loops, best of 3: 1.26 us per loop In [4]: %timeit if a == b == 5: pass 100000 loops, best of 3: 1.97 us per loop _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
