quetion about "+=" and "runtime"

[gagaguy]

1.i saw "+=" in a program code,but i haven't see it before,neither can
i find it in a cook,who can tell me the usage of "python0"

2.how can i know how long does a program run?

[Terry Reedy]

<ga*****@gmail.com> wrote in message
news:11**********************@g47g2000cwa.googlegr oups.com...

1.i saw "+=" in a program code,but i haven't see it before,neither can
i find it in a cook,who can tell me the usage of "python0"
It probably is in the tutorial and certainly is in the reference manual.
I don't understand "usage of 'python0'".
2.how can i know how long does a program run?

time module

tjr

[gagaguy]

1.i have look " += " up,but i can't find it.is it ofthen used?
2.i saq a result like this in a web page:
$ time python permute2.py 56789 3
Got 120 items.
Maximum at 87596 ,product 84000

real 0m0.057s
user 0m0.050s
sys 0m0.000s

$ time python permute3.py 56789 3
Got 120 items.
Maximum at 87596 ,product 84000

real 0m0.040s
user 0m0.030s
sys 0m0.010s

i wanna know how to call out this

[Robert Kern]

ga*****@gmail.com wrote:

1.i have look " += " up,but i can't find it.
http://docs.python.org/ref/augassign.html
is it ofthen used?
Reasonably so.
2.i saq a result like this in a web page:
$ time python permute2.py 56789 3
Got 120 items.
Maximum at 87596 ,product 84000

real 0m0.057s
user 0m0.050s
sys 0m0.000s

$ time python permute3.py 56789 3
Got 120 items.
Maximum at 87596 ,product 84000

real 0m0.040s
user 0m0.030s
sys 0m0.010s

i wanna know how to call out this

As Terry said, look at the "time" module. Don't use the "time" program
(a standard program on UNIX-like systems) unless you actually want to
time the startup of the interpreter too rather than just the code itself.

--
Robert Kern
rk***@ucsd.edu

"In the fields of hell where the grass grows high
Are the graves of dreams allowed to die."
-- Richard Harter