python · terryjreedy · Aug 27, 2023 · May 29, 2023 · May 29, 2023 · May 29, 2023
diff --git a/Doc/library/timeit.rst b/Doc/library/timeit.rst
@@ -52,6 +52,8 @@ A callable can also be passed from the :ref:`python-interface`::
 Note however that :func:`.timeit` will automatically determine the number of
 repetitions only when the command-line interface is used.  In the
 :ref:`timeit-examples` section you can find more advanced examples.
+Especially, the time unit can be changed by modifying :func:`default_timer`
+or passing other timer in function.
 
 
 .. _python-interface:
@@ -124,7 +126,7 @@ The module defines three convenience functions and a public class:
 
       Time *number* executions of the main statement.  This executes the setup
       statement once, and then returns the time it takes to execute the main
-      statement a number of times, measured in seconds as a float.
+      statement a number of times, measured in seconds as a float by default timer.
       The argument is the number of times through the loop, defaulting to one
       million.  The main statement, the setup statement and the timer function
       to be used are passed to the constructor.

diff --git a/Lib/timeit.py b/Lib/timeit.py
@@ -50,9 +50,9 @@
 """
 
 import gc
+import itertools
 import sys
 import time
-import itertools
 
 __all__ = ["Timer", "timeit", "repeat", "default_timer"]
 
@@ -77,9 +77,11 @@ def inner(_it, _timer{init}):
     return _t1 - _t0
 """
 
+
 def reindent(src, indent):
     """Helper to reindent a multi-line statement."""
-    return src.replace("\n", "\n" + " "*indent)
+    return src.replace("\n", "\n" + " " * indent)
+
 
 class Timer:
     """Class for timing execution speed of small code snippets.
@@ -166,7 +168,8 @@ def timeit(self, number=default_number):
 
         To be precise, this executes the setup statement once, and
         then returns the time it takes to execute the main statement
-        a number of times, as a float measured in seconds.  The
+        a number of times, as a float measured in seconds if using default
+        timer.Thus,time unit could be changed if giving other timer.  The
         argument is the number of times through the loop, defaulting
         to one million.  The main statement, the setup statement and
         the timer function to be used are passed to the constructor.
@@ -228,16 +231,19 @@ def autorange(self, callback=None):
                     return (number, time_taken)
             i *= 10
 
+
 def timeit(stmt="pass", setup="pass", timer=default_timer,
            number=default_number, globals=None):
     """Convenience function to create Timer object and call timeit method."""
     return Timer(stmt, setup, timer, globals).timeit(number)
 
+
 def repeat(stmt="pass", setup="pass", timer=default_timer,
            repeat=default_repeat, number=default_number, globals=None):
     """Convenience function to create Timer object and call repeat method."""
     return Timer(stmt, setup, timer, globals).repeat(repeat, number)
 
+
 def main(args=None, *, _wrap_timer=None):
     """Main program, used when run as a script.
 
@@ -269,7 +275,7 @@ def main(args=None, *, _wrap_timer=None):
 
     timer = default_timer
     stmt = "\n".join(args) or "pass"
-    number = 0 # auto-determine
+    number = 0  # auto-determine
     setup = []
     repeat = default_repeat
     verbose = 0
@@ -286,7 +292,7 @@ def main(args=None, *, _wrap_timer=None):
                 time_unit = a
             else:
                 print("Unrecognized unit. Please select nsec, usec, msec, or sec.",
-                    file=sys.stderr)
+                      file=sys.stderr)
                 return 2
         if o in ("-r", "--repeat"):
             repeat = int(a)
@@ -320,7 +326,7 @@ def callback(number, time_taken):
                 msg = "{num} loop{s} -> {secs:.{prec}g} secs"
                 plural = (number != 1)
                 print(msg.format(num=number, s='s' if plural else '',
-                                  secs=time_taken, prec=precision))
+                                 secs=time_taken, prec=precision))
         try:
             number, _ = t.autorange(callback)
         except:
@@ -371,5 +377,6 @@ def format_time(dt):
                                UserWarning, '', 0)
     return None
 
+
 if __name__ == "__main__":
     sys.exit(main())
diff --git a/Misc/NEWS.d/next/Documentation/2023-05-29-14-10-24.gh-issue-105052.MGFwbm.rst b/Misc/NEWS.d/next/Documentation/2023-05-29-14-10-24.gh-issue-105052.MGFwbm.rst
@@ -0,0 +1 @@
+timeit doc update
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1 @@
		timeit doc update
terryjreedy marked this conversation as resolved. Show resolved Hide resolved