Issue6422 add autorange method to timeit.Timer
diff --git a/Lib/timeit.py b/Lib/timeit.py
index 98cb3eb..2770efa 100644
--- a/Lib/timeit.py
+++ b/Lib/timeit.py
@@ -207,6 +207,26 @@
r.append(t)
return r
+ def autorange(self, callback=None):
+ """Return the number of loops so that total time >= 0.2.
+
+ Calls the timeit method with *number* set to successive powers of
+ ten (10, 100, 1000, ...) up to a maximum of one billion, until
+ the time taken is at least 0.2 second, or the maximum is reached.
+ Returns ``(number, time_taken)``.
+
+ If *callback* is given and is not None, it will be called after
+ each trial with two arguments: ``callback(number, time_taken)``.
+ """
+ for i in range(1, 10):
+ number = 10**i
+ time_taken = self.timeit(number)
+ if callback:
+ callback(number, time_taken)
+ if time_taken >= 0.2:
+ break
+ return (number, time_taken)
+
def timeit(stmt="pass", setup="pass", timer=default_timer,
number=default_number, globals=None):
"""Convenience function to create Timer object and call timeit method."""
@@ -295,17 +315,16 @@
t = Timer(stmt, setup, timer)
if number == 0:
# determine number so that 0.2 <= total time < 2.0
- for i in range(1, 10):
- number = 10**i
- try:
- x = t.timeit(number)
- except:
- t.print_exc()
- return 1
- if verbose:
- print("%d loops -> %.*g secs" % (number, precision, x))
- if x >= 0.2:
- break
+ callback = None
+ if verbose:
+ def callback(number, time_taken):
+ msg = "{num} loops -> {secs:.{prec}g} secs"
+ print(msg.format(num=number, secs=time_taken, prec=precision))
+ try:
+ number, _ = t.autorange(callback)
+ except:
+ t.print_exc()
+ return 1
try:
r = t.repeat(repeat, number)
except: