How to increase the speed of this program?

[Peter Otten]

Peter Otten wrote:

> HYRY wrote:
> 
>> I want to join two mono wave file to a stereo wave file by only using
>> the default python module.
>> Here is my program, but it is much slower than the C version, so how
>> can I increase the speed?
>> I think the problem is at line #1, #2, #3.
> 
>> oarray = array.array("h", [0]*(len(larray)+len(rarray))) #1
> 
> ITEMSIZE = 2
> size = ITEMSIZE*(len(larray) + len(rarray))
> oarray = array.array("h")
> oarray.fromstring("\0" * size)
> 
> may be a bit faster.

Confirmed:

$ python2.5 -m timeit -s'from array import array; N = 10**6' 'a =
array("h"); a.fromstring("\0"*(2*N))'
100 loops, best of 3: 9.68 msec per loop
$ python2.5 -m timeit -s'from array import array; N = 10**6' 'a = array("h",
[0]*N);'
10 loops, best of 3: 199 msec per loop

Peter