[Python-checkins] python/dist/src/Lib timeit.py,1.2,1.3

[gvanrossum@users.sourceforge.net]

Update of /cvsroot/python/python/dist/src/Lib
In directory sc8-pr-cvs1:/tmp/cvs-serv20902

Modified Files:
	timeit.py 
Log Message:
Add notes about baseline overhead, and about different Python
versions.  Add -h/--help option to print doc string.


Index: timeit.py
===================================================================
RCS file: /cvsroot/python/python/dist/src/Lib/timeit.py,v
retrieving revision 1.2
retrieving revision 1.3
diff -C2 -d -r1.2 -r1.3
*** timeit.py	6 Mar 2003 02:32:19 -0000	1.2
--- timeit.py	6 Mar 2003 03:02:10 -0000	1.3
***************
*** 8,12 ****
  
  Command line usage:
!     python timeit.py [-n N] [-r N] [-s S] [-t] [-c] [statement]
  
  Options:
--- 8,12 ----
  
  Command line usage:
!     python timeit.py [-n N] [-r N] [-s S] [-t] [-c] [-h] [statement]
  
  Options:
***************
*** 16,19 ****
--- 16,20 ----
    -t/--time: use time.time() (default on Unix)
    -c/--clock: use time.clock() (default on Windows)
+   -h/--help: print this usage message and exit
    statement: statement to be timed (default 'pass')
  
***************
*** 34,42 ****
  repeat the timing a few times and use the best time; the -r option is
  good for this.  On Unix, you can use clock() to measure CPU time.
  """
  
  # 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, count), use [None]*count.  It's barely slower.
  
  import sys
--- 35,54 ----
  repeat the timing a few times and use the best time; the -r option is
  good for this.  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 (especially when comparing different versions of
+ Python).  The baseline overhead is measured by invoking the program
+ without arguments.
  """
  
  # 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.
  
  import sys
***************
*** 142,150 ****
      import getopt
      try:
!         opts, args = getopt.getopt(args, "n:s:r:tc",
                                     ["number=", "setup=", "repeat=",
!                                     "time", "clock"])
      except getopt.error, err:
          print err
          return 2
      timer = default_timer
--- 154,163 ----
      import getopt
      try:
!         opts, args = getopt.getopt(args, "n:s:r:tch",
                                     ["number=", "setup=", "repeat=",
!                                     "time", "clock", "help"])
      except getopt.error, err:
          print err
+         print "use -h/--help for command line help"
          return 2
      timer = default_timer
***************
*** 162,169 ****
              if repeat <= 0:
                  repeat = 1
!         if o in ("-t", "time"):
              timer = time.time
!         if o in ("-c", "clock"):
              timer = time.clock
      t = Timer(stmt, setup, timer)
      if number == 0:
--- 175,185 ----
              if repeat <= 0:
                  repeat = 1
!         if o in ("-t", "--time"):
              timer = time.time
!         if o in ("-c", "--clock"):
              timer = time.clock
+         if o in ("-h", "--help"):
+             print __doc__,
+             return 0
      t = Timer(stmt, setup, timer)
      if number == 0: