A timer as a context manager
contexttimer
provides you with a couple of utilities to quickly measure the execution time of a code block or a function.
Timer as a context manager
contexttimer.Timer
is a context manager measuring the execution time of the code block it contains.
The elapsed time is accessible through the elapsed
property.
with Timer() as t:
... # some code here
print t.elapsed
a value in seconds
The contexttimer.Timer
context manager
contexttimer.Timer
is a context manager <http://docs.python.org/reference/datamodel.html#context-managers>
_ with 2 parameters and a public property:
default_timer
: a platform specific timer function (time.time
for Unix platforms and time.clock
for Windows platforms). You can instanciate a Timer
object with your own timer, by passing it to the constructor.
factor
: a multiplying factor applied to the elapsed
property. For example, a factor or 1000 will lead to elapsed
being expressed in milliseconds instead of seconds. Default value of 1.
elapsed
: (read only property) the wall clock timing of the execution of the code block, in seconds. By default, expressed in seconds.
Example
"""""""
from contexttimer import Timer
with Timer(factor=1000) as t:
... for i in xrange(10000000):
... pass
...
print(t.elapsed)
73.6618041992 # in miliseconds
Note that elapsed
is calculated on demand, so it is possible to time sub-parts of your code block:
with Timer(factor=1000) as t:
... # do some things
... print t.elapsed
... # do other tings
... print t.elapsed
...
10.122 # in ms
20.567
The contexttimer.timer
function decorator
You can use the @timer
function decorator to measure the time execution of an entire function.
When the function returns its value, its execution time will be printed to the stdout (default), or to the argument logger.
Examples
""""""""
@timer
... def sleep_for_2s():
... time.sleep(2)
sleep_for_2s()
function sleep_for_2s execution time: 2.002
logging.basicConfig()
@timer(logger=logging.getLogger())
... def sleep_for_2s():
... time.sleep(2)
sleep_for_2s()
DEBUG:root:function blah execution time: 2.002
As it makes use of the Timer
context manager inside, all arguments passed to the @timer
decorator will be used a Timer
init arguments.
Example:
""""""""
@timer(factor=1000)
... def sleepawhile(n):
... time.sleep(n)
...
sleepawhile(2)
function sleepawhile execution time: 2000.089
The contexttimer.timeout.timeout
decorator
You can use the @timeout
function decorator to stop a function/method call and call a handler if the call exceeds a fixed amount of time.
Example:
""""""""
def timeout_handler(limit, f, *args, **kwargs):
... print "{func} call timed out after {lim}s.".format(
... func=f.name, lim=limit)
...
@timeout(limit=5, handler=timeout_handler)
... def work(foo, bar, baz="spam")
... time.sleep(10)
work("foo", "bar", "baz")
time passes...
work call timed out after 5s.
Thanks
Thanks to halloi, wolanko and Jon Blackburn for their helpful insights and contributions.
License
contexttimer
is released under the GPLv3 license.