If -n is not given, a suitable number of loops is calculated by trying
successive powers of 10 until the total time is at least 0.2 seconds.
-The difference in default timer function is because on Windows,
-clock() has microsecond granularity but time()'s granularity is 1/60th
-of a second; on Unix, clock() has 1/100th of a second granularity and
-time() is much more precise. On either platform, the default timer
-functions measure wall clock time, not the CPU time. This means that
-other processes running on the same computer may interfere with the
-timing. The best thing to do when accurate timing is necessary is to
-repeat the timing a few times and use the best time. The -r option is
-good for this; the default of 3 repetitions is probably enough in most
-cases. On Unix, you can use clock() to measure CPU time.
-
Note: there is a certain baseline overhead associated with executing a
-pass statement. The code here doesn't try to hide it, but you should
-be aware of it. The baseline overhead can be measured by invoking the
-program without arguments.
-
-The baseline overhead differs between Python versions! Also, to
-fairly compare older Python versions to Python 2.3, you may want to
-use python -O for the older versions to avoid timing SET_LINENO
-instructions.
+pass statement. It differs between versions. The code here doesn't try
+to hide it, but you should be aware of it. The baseline overhead can be
+measured by invoking the program without arguments.
+
+Classes:
+
+ Timer
+
+Functions:
+
+ timeit(string, string) -> float
+ repeat(string, string) -> list
+ default_timer() -> float
+
"""
import gc
import sys
import time
-try:
- import itertools
-except ImportError:
- # Must be an older Python version (see timeit() below)
- itertools = None
+import itertools
-__all__ = ["Timer"]
+__all__ = ["Timer", "timeit", "repeat", "default_timer"]
dummy_src_name = "<timeit-src>"
default_number = 1000000
to one million. The main statement, the setup statement and
the timer function to be used are passed to the constructor.
"""
- if itertools:
- it = itertools.repeat(None, number)
- else:
- it = [None] * number
+ it = itertools.repeat(None, number)
gcold = gc.isenabled()
gc.disable()
try:
projects / python / commitdiff