The `timeit` command#

This uses the function sage_timeit().

class sage.misc.sage_timeit_class.SageTimeit[source]#

Bases: object

Time execution of a command or block of commands.

Displays the best WALL TIME for execution of the given code. This is based on the Python timeit module, which avoids a number of common traps for measuring execution times. It is also based on IPython’s %timeit command.

TYPICAL INPUT FORMAT:

timeit(statement, preparse=None, number=0, repeat=3, precision=3)

EXAMPLES:

Sage

sage: timeit('2^10000')
625 loops, best of 3: ... per loop

Python

>>> from sage.all import *
>>> timeit('2^10000')
625 loops, best of 3: ... per loop

We illustrate some options:

Sage

sage: timeit('2+2',precision=2,number=20,repeat=5)
20 loops, best of 5: ... per loop

Python

>>> from sage.all import *
>>> timeit('2+2',precision=Integer(2),number=Integer(20),repeat=Integer(5))
20 loops, best of 5: ... per loop

The preparser is on by default (if it is on), but the preparse option allows us to override it:

Sage

sage: timeit('2^10000', preparse=False, number=50)
50 loops, best of 3: ... per loop

Python

>>> from sage.all import *
>>> timeit('2^10000', preparse=False, number=Integer(50))
50 loops, best of 3: ... per loop

The input can contain newlines:

Sage

sage: timeit("a = 2\nb=131\nfactor(a^b-1)", number=25)                          # needs sage.libs.pari
25 loops, best of 3: ... per loop

Python

>>> from sage.all import *
>>> timeit("a = 2\nb=131\nfactor(a^b-1)", number=Integer(25))                          # needs sage.libs.pari
25 loops, best of 3: ... per loop

See also

runsnake()

eval(code, globs=None, locals=None, **kwds)[source]#

This eval function is called when doing %timeit in the notebook.

INPUT:

code – string of code to evaluate; may contain newlines.
globs – global variables; if not given, uses module scope globals.
locals – ignored completely.
kwds – passed onto sage_timeit. Common options are preparse, number, repeat, precision. See sage_timeit() for details.

OUTPUT: string – timing information as a string

EXAMPLES:

Sage

sage: timeit.eval("2+2")                     # random output
'625 loops, best of 3: 1.47 us per loop'

Python

>>> from sage.all import *
>>> timeit.eval("2+2")                     # random output
'625 loops, best of 3: 1.47 us per loop'

We emphasize that timeit times WALL TIME. This is good in the context of Sage where commands often call out to other subprocesses that do not appear in CPU time.

Sage

sage: timeit('sleep(float(0.5))', number=3)  # long time (5s on sage.math, 2012)
3 loops, best of 3: ... ms per loop

Python

>>> from sage.all import *
>>> timeit('sleep(float(0.5))', number=Integer(3))  # long time (5s on sage.math, 2012)
3 loops, best of 3: ... ms per loop

The timeit command#

The `timeit` command#