writing large files quickly

Tim Chase python.list at tim.thechases.com
Fri Jan 27 20:24:48 CET 2006


> Untested, but this should be faster.
> 
> block = '0' * 409600
> fd = file('large_file.bin', 'wb')
> for x in range(1000):
>      fd.write('0')
> fd.close()

Just checking...you mean

	fd.write(block)

right? :)  Otherwise, you end up with just 1000 "0" characters in 
your file :)

Is there anything preventing one from just doing the following?

	fd.write("0" * 409600000)

It's one huge string for a very short time.  It skips all the 
looping and allows Python to pump the file out to the disk as 
fast as the OS can handle it. (and sorta as fast as Python can 
generate this humongous string)

-tkc








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