[Tutor] Converting a list to a string

[Pedro Diaz Jimenez]

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On Monday 07 May 2001 11:15, Michael P. Reilly wrote:
> Praveen Pathiyil wrote
>
> > Hi all,
> >
> > If i have a list=20
> > status =3D ['tftp>', 'Sent', '1943', 'bytes', 'in', '0.0', 'seconds'],
> > is there a single command which will give me a string=20
> > tftp> Sent 1943 bytes in 0.0 seconds
> >
> > OR do i have to do=20
> >
> > stat_str =3D ''
> > for elt in status:
> >     stat_str =3D stat_str + ' ' + elt
>
> You don't _have_ to do that; in fact, concatenating strings that way is
> very inefficient (the left hand of the '+' is copied each time through the
> loop).  There is a join function/method for strings to do this for you.
>
> In Python 2.0 and higher, you can use string methods, but on the joiner
> (in this case the space):
>   stat_str = ' '.join(status)
>
> In earlier releases, use the join function in the string module:
>   import string
>   stat_str = string.join(status)
>
> Also, if you use the loop above, you'll have an extra space in the
> front of the resulting string.  You won't get that with the join
> routines.
>
>   -Arcege

Python 1.5.2 (#0, Dec 27 2000, 13:59:38)  [GCC 2.95.2 20000220 (Debian 
GNU/Linux)] on linux2
Copyright 1991-1995 Stichting Mathematisch Centrum, Amsterdam
>>> A=['a','b','c','d','e']
>>> reduce( lambda x,y:x+y, A )
'abcde'
>>> reduce( lambda x,y:x+" "+y,A
... )
'a b c d e'
>>>

Just my 0.02

Cheers
Pedro

- -- 

/*
 * Pedro Diaz Jimenez
 * pdiaz88@terra.es 
 * pdiaz@acm.asoc.fi.upm.es
 *
 * Wanna see how 100000! looks like?:
 * http://acm.asoc.fi.upm.es/~pdiaz/fact_100.000
 * 
 * La sabiduria me persigue, pero yo soy mas rapido
 */
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