Broke down and made it work for Python 2.0 and up. (Older versions
would have required refraining from using string methods -- too
painful.)
Changed the -s option so that multiple -s options are cumulative.
diff --git a/Lib/timeit.py b/Lib/timeit.py
index 2178d52..f244b73 100644
--- a/Lib/timeit.py
+++ b/Lib/timeit.py
@@ -1,4 +1,4 @@
-"""Framework for measuring execution time for small code snippets.
+"""Tool for measuring execution time of small code snippets.
This module avoids a number of common traps for measuring execution
times. See also Tim Peters' introduction to the Algorithms chapter in
@@ -12,7 +12,7 @@
Options:
-n/--number N: how many times to execute 'statement' (default: see below)
-r/--repeat N: how many times to repeat the timer (default 1)
- -s/--setup S: statements executed once before 'statement' (default 'pass')
+ -s/--setup S: statement to be executed once initially (default 'pass')
-t/--time: use time.time() (default on Unix)
-c/--clock: use time.clock() (default on Windows)
-h/--help: print this usage message and exit
@@ -20,7 +20,8 @@
A multi-line statement may be given by specifying each line as a
separate argument; indented lines are possible by enclosing an
-argument in quotes and using leading spaces.
+argument in quotes and using leading spaces. Multiple -s options are
+treated similarly.
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.
@@ -37,27 +38,23 @@
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 (especially when comparing different versions of
-Python). The baseline overhead is measured by invoking the program
-without arguments.
+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.
"""
-# To use this module with older versions of Python, the dependency on
-# the itertools module is easily removed; in the template, instead of
-# itertools.repeat(None, number), use [None]*number. It's barely
-# slower. Note: the baseline overhead, measured by the default
-# invocation, differs for older 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.
-
-# XXX Maybe for convenience of comparing with previous Python versions,
-# itertools.repeat() should not be used at all?
-
import sys
import math
import time
-import itertools
+try:
+ import itertools
+except ImportError:
+ # Must be an older Python version (see timeit() below)
+ itertools = None
__all__ = ["Timer"]
@@ -75,9 +72,8 @@
# in Timer.__init__() depend on setup being indented 4 spaces and stmt
# being indented 8 spaces.
template = """
-def inner(number, timer):
+def inner(seq, timer):
%(setup)s
- seq = itertools.repeat(None, number)
t0 = timer()
for i in seq:
%(stmt)s
@@ -126,7 +122,11 @@
to one million. The main statement, the setup statement and
the timer function to be used are passed to the constructor.
"""
- return self.inner(number, self.timer)
+ if itertools:
+ seq = itertools.repeat(None, number)
+ else:
+ seq = [None] * number
+ return self.inner(seq, self.timer)
def repeat(self, repeat=default_repeat, number=default_number):
"""Call timer() a few times.
@@ -177,13 +177,13 @@
timer = default_timer
stmt = "\n".join(args) or "pass"
number = 0 # auto-determine
- setup = "pass"
+ setup = []
repeat = 1
for o, a in opts:
if o in ("-n", "--number"):
number = int(a)
if o in ("-s", "--setup"):
- setup = a
+ setup.append(a)
if o in ("-r", "--repeat"):
repeat = int(a)
if repeat <= 0:
@@ -195,6 +195,7 @@
if o in ("-h", "--help"):
print __doc__,
return 0
+ setup = "\n".join(setup) or "pass"
t = Timer(stmt, setup, timer)
if number == 0:
# determine number so that 0.2 <= total time < 2.0