should writing Unicode files be so slow

[Antoine Pitrou]

Le Fri, 19 Mar 2010 17:18:17 +0000, djc a écrit :
> 
> changing
> with open(filename, 'rU') as tabfile: to
> with codecs.open(filename, 'rU', 'utf-8', 'backslashreplace') as
> tabfile:
> 
> and
> with open(outfile, 'wt') as out_part: to
> with codecs.open(outfile, 'w', 'utf-8') as out_part:
> 
> causes a program that runs  in
> 43 seconds to take 4 minutes to process the same data.

codecs.open() (and the object it returns) is slow as it is written in 
pure Python.

Accelerated reading and writing of unicode files is available in Python 
2.7 and 3.1, using the new `io` module.

Regards

Antoine.