On Sep 4, 2:06 pm, Duncan Booth <[EMAIL PROTECTED]> wrote:
> [EMAIL PROTECTED] wrote:
> >> But watch out if the lists aren't all the same length: zip won't pad out
> >> any sequences, so it maynotbe exactly what is wanted here:
>
> >> >>> x = ['1', '2', '3']
> >> >>> y = ['4', '5']
> >> >>> for row in zip(x,y):
>
> >> print ', '.join(row)
>
> >> 1, 4
> >> 2, 5
>
> > Unfortunately the lists will be of different sizes
>
> In that case use:
>
> from itertools import repeat, chain, izip
> def izip_longest(*args, **kwds):
> fillvalue = kwds.get('fillvalue')
> def sentinel(counter = ([fillvalue]*(len(args)-1)).pop):
> yield counter() # yields the fillvalue, or raises IndexError
> fillers = repeat(fillvalue)
> iters = [chain(it, sentinel(), fillers) for it in args]
> try:
> for tup in izip(*iters):
> yield tup
> except IndexError:
> pass
>
> x = ['1', '2', '3']
> y = ['4', '5']
> for row in izip_longest(x,y, fillvalue='*'):
> print ', '.join(row)
>
> which gives:
>
> 1, 4
> 2, 5
> 3, *
>
> (izip_longest is in a future version of itertools, but for
> now you have to define it yourself).
Thanks guys
I have a list of lists such as
a = ["1" , "2"] b = ["4", "5", "6"] c = ["7",8", "9"]
Stored in another list: d = [a,b,c]
I know this makes me sound very stupid but how would I specify
in the parameter the inner lists without having to write them all out
such as:
for row in izip_longest(d[0], d[1], d[2], fillvalue='*'):
print ', '.join(row)
i.e. How could I do the following if I didn't know how many list of
lists I had.
Sorry this sounds stupid and easy.
Thankyou very much in advance as well, you are all very helpful
indeed.
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