create a tmp file for system execution

[Bengt Richter]

On 29 May 2002 19:54:05 GMT, bokr at oz.net (Bengt Richter) wrote:

>On Wed, 29 May 2002 15:34:57 +0100, Eric Texier <erict at millfilm.co.uk> wrote:
>
>>I have a py script executing a bunch of os.system in a loop.
>>It is not very fast and I was wondering if it will not be better
>>to recreate a execution file.
>>
>>My 2 questions:
>>
>>1) what is faster for a big number of call
>>
>>for i in range(1,2000):
>>    os.system("ls  F1.%d   F2.%d" % ( i , i ) "  )
>>
>>OR
>>
>>fileOut = open("tmpFile",w)
>>for i in range(1,2000):
>>    fileOut.write("ls  F1.%d   F2.%d" % ( i , i ) " )
>>
>>fileOut.close()
>>os.system("csh -c 'source tmpFile' ")
>>os.system("rm -f tmpFile")
>>
>>
>>2) if the second one is better I would like to kwo if there is any thing
>>
>>in python for temporary file, the drag being to if you do not come for
>>a specific naming mechanism, you file can be change by and other
>>process before it execute
>>
>wouldn't it be faster to do a single ls F.* command piped to a grep for
>the decimal extensions, then to a python script for sorting and final formatting
>or whatever you want to do with the file names? Or am I missing something?
>
Forgot to mention the glob module, using which (along with os.path.isdir,
os.path.isfile, etc.) you can probably do everything you want from python.

Regards,
Bengt Richter