无法了解时间输出

Question

my problem is this:

>>> 999 in list(xrange(1000))
True # this takes a glimpse

Instead:

>>> import timeit
>>> timeit.timeit('999 in list(xrange(1000))')
26.88947892189026

Why does timeit gives such a high output?

Thank you

Answer 1

Because it does this 1 million times !
https://docs.python.org/3.4/library/timeit.html#timeit.timeit

---

timeit.timeit takes a positional argument number which defaults to 1.000.000 so it indeed takes longer to do the statement 1 million times compared to only one.

If you do this 1 time, it's way faster :

In [2]: timeit.timeit('999 in list(xrange(1000))')
Out[2]: 31.733104944229126

In [3]: timeit.timeit('999 in list(xrange(1000))', number=1)
Out[3]: 4.5061111450195312e-05

Answer 2

timeit.timeit(stmt='pass', setup='pass', timer=<default timer>, number=1000000)

Stupid question, the default number of times the statement is executed is one million... I should have read timeit doc before...

>>> timeit.timeit('999 in list(xrange(1000))', number=1)
9.083747863769531e-05