On 08/07/2014 03:06 PM, Chris Barker wrote:
[snip timings, etc.]
I don't remember where, but I believe that cPython has an optimization built in for repeated string concatenation, which
is probably why you aren't seeing big differences between the + and the sum().
A little testing shows how to defeat that optimization:
blah = ''
for string in ['booyah'] * 100000:
blah = string + blah
Note the reversed order of the addition.
--> timeit.Timer("for string in ['booya'] * 100000: blah = blah + string", "blah =
''").repeat(3, 1)
[0.021117210388183594, 0.013692855834960938, 0.00768280029296875]
--> timeit.Timer("for string in ['booya'] * 100000: blah = string + blah", "blah =
''").repeat(3, 1)
[15.301048994064331, 15.343288898468018, 15.268463850021362]
--
~Ethan~
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