Ben Bacarisse wrote, on February 23, 2017 4:24 PM > > "Deborah Swanson" <pyt...@deborahswanson.net> writes: > > >> -----Original Message----- > >> From: Erik [mailto:pyt...@lucidity.plus.com] > >> Sent: Thursday, February 23, 2017 2:09 AM > >> To: pyt...@deborahswanson.net; python-list@python.org > >> Subject: Re: Namedtuples problem > >> > >> > >> Hi, > >> > >> On 23/02/17 09:38, Deborah Swanson wrote: > >> > group[[idx][records_idx[label]]] > >> > gets an IndexError: list index out of range > >> > >> [snip] > >> > >> > Can anyone see why I'm getting this Index error? and how > to fix it? > >> > >> It looks to me like you are indexing into a single-element > >> list that you > >> are creating using the literal list syntax in the middle of > >> the expression. > > > > Actually, group is essentially a 2-element list. Each group > has a list > > of rows, and each row has a set of fields. group has to be > indexed by > > row index and field index. (This is a namedtuple configuration.) > > > > The weirdness is that > > > > group[0][4] > > Sure. No trouble there. > > > gets the right answer, but > > > > group[[idx][records_idx[label]]], > > where idx = 0 and records_idx[label]] = 4 > > > > gets the IndexError. > > group is not involved in the index error. Just write > > [idx][records_idx[label]] > > and you'll get the error. Wrapping that up in group[...] > won't make a difference. In fact, since idx is 0 and > records_idx[label]] is 4, you get the same error (for the > same reason) by typing > > [0][4] > > into a Python REPL. Does it still seem weird?
No, and you also put your finger on (psrt of) the real problem. See the reply I just sent to MRAB. > This is just another shot at explaining the issue because, > sometimes, different words can help. I thought the message > you are replying to (as well as others) explained it well, > but it obviously it did not hit the spot. > > <snip> > -- > Ben No, the spot wasn't getting hit, but it has been now. Thanks for replying. -- https://mail.python.org/mailman/listinfo/python-list
