Quick aside, you can insert tuples without much effort: `points += ((3,5),)`
And also that I can't do the reverse, i.e.: >>> foo = tuple() >>> foo += [5,6] Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: can only concatenate tuple (not "list") to tuple On Sun, Nov 4, 2012 at 10:57 PM, Ulrich Eckhardt <dooms...@knuut.de> wrote: > Hi everybody! > > I was just smacked by some very surprising Python 2.7 behaviour. I was > assembling some 2D points into a list: > > points = [] > points += (3, 5) > points += (4, 6) > > What I would have expected is to have [(3, 5), (4, 6)], instead I got [3, > 5, 4, 6]. My interpretations thereof is that the tuple (x, y) is iterable, > so the elements are appended one after the other. Actually, I should have > used points.append(), but that's a different issue. > > Now, what really struck me was the fact that [] + (3, 5) will give me a > type error. Here I wonder why the augmented assignment behaves so much > different. > > Can anyone help me understand this? > > Thanks! > > Uli > > > -- > http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list
