On 13 May, 18:18, Tim Chase <python.l...@tim.thechases.com> wrote: > On 05/13/2010 10:45 AM, a wrote: > > > > > > >>> a=[2,3,3,4,5,6] > > >>> i want to know the indices where a==3 (ie 1 and 2) > > >> indexes = [i for (i, v) in enumerate(a) where v==3] > > >>> then i want to reference these in a > > >> In a _what_? You can then do things like > > >> for i in indexes: > >> print a[i] > > >> (but you already know these are "3", so it's not very exciting...) > > >> -tkc > > > really its to get the indexes in 1 array where something equals > > something then reference these in another array. > > If your two arrays are of the same length, you can do things like > > a = [2,3,3,4,5,6] > b = ['a', 'b', 'c', 'd', 'e', 'f'] > > print [m for (n,m) in zip(a,b) if n == 3] > > and skip the indexes altogether. > > -tkc
mmm, that's clever, thanks. although i don't know why it works yet. at least i found a good user group! -- http://mail.python.org/mailman/listinfo/python-list
