[Tutor] String format question

[andy surany]

Thanks Jeff.

Maybe I can explain it a little better....

I am obtaining data from multiple databases. Any data which is not in
character format is converted. The data is then formatted into a single
string which is displayed in a scrolled list.

I am using the map/lambda combination to concatenate the individual data
elements. The results are simply pushed to a ScrolledList function for
display.

I tried using the string formatting operator as well as .ljust. The
problem is that these are true "formatting" controls - which are good
for print, etc. But they are invalid (lost) when concatenating a string.
Or at least they are lost the way that I have tried to do it.....

Maybe a simpler look would be:

string=a[i]+b[i]+c[i]

Now I need a,b, and c to always begin at the same position within
"string".

Regards,

Andy


-----Original Message-----
From: Jeff Shannon <jeff@ccvcorp.com>
To: andy surany <mongo57a@comcast.net>
Cc: tutor@python.org <tutor@python.org>
Date: Wednesday, November 27, 2002 3:25 PM
Subject: Re: [Tutor] String format question


>
>
>andy surany wrote:
>
>> # The individual contents of a,b, & c can be variable lengths.
>> #
>> # Now I use "map" to concatenate the individual records
>> options=map((lambda i: a[i]+b[i]+c[i]),range(nrecs)
>> self.ScrolledList(options) # This function populates the list.
>>
>> This is what the output looks like:
>>
>> aaa bbb ccc
>> aaa bb ccccc
>> a b c
>
>Use the string formatting operator, %.
>
>(Note:  I'm not sure what you're trying to do, exactly with the
map/lambda
>combination that wouldn't be much clearer with a simple for loop or
list
>comprehension...)
>
>    options = map( (lambda i: "%5s %5s %5s" % (a[i], b[i], c[i])),
>range(nrecs) )
>
>Writing this as a list comprehension would give you this:
>
>    options = ["%5s %5s %5s" % (a[i], b[i], c[i]) for i in
range(nrecs)]
>
>which seems a little clearer to *me* at least, but that may be a matter
of
>taste.  (I do have a personal dislike of the lambda syntax...)
>
>Depending on where you get your a, b, and c lists, though, you may be
able
>to improve this even more.  If they all come from a related source, you
may
>be able to combine them into a single list of tuples -- converting from
your
>three lists to a single list of tuples would look like this:
>
>    optionlist = [ (a[i], b[i], c[i]) for i in range(nrecs) ]
>
>but this would probably only be efficient if you can build the single
list
>*instead of* the three separate lists.  If you *can* do that, then the
list
>comp above becomes dead simple:
>
>    options = ["%5s %5s %5s" % opt for opt in optionlist]
>
>Thus eliminating the need to generate a range.
>
>Also note that, if you need the strings to be left-justified instead of
>right-justified, you can simply use a negative sign on the numbers --
"%-5s
>%-5s %-5s"
>
>Jeff Shannon
>Technician/Programmer
>Credit International
>
>
>
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