Hi Reinis Danne I am not sure if this is exactly the cause of your problem, but map() returns a list in Python 2 but an iterator in Python 3.
You can place a list around map() like: list(map(self.paper.delete, items)) to ensure that the result is still a list and has the same behavior in both Python 2 and 3. Another difference is that in Python 2 map() continues until the items in the longest of the iterator is exhausted, extending the other arguments with None. In Python 3 this is not the case, a similar behavior can be achieved using itertools.zip_longest. So I guess, your problem is related to one of the above two issues. BTW, really nice program there you have built. regards Bhaskar On 2/5/16, Michael Lange <klappn...@web.de> wrote: > Hi, > > I'm glad you finally got it working! > > On Fri, 5 Feb 2016 16:56:58 +0200 > Reinis Danne <rei4...@gmail.com> wrote: > > (...) >> Replacing this: >> map(self.paper.delete, items) >> >> with this: >> for i in items: >> self.paper.delete(i) >> >> fixes the problem. >> >> I don't understand why the difference. That code is equivalent in >> both cases as far as I know. Is there a bug or I'm using map() >> incorrectly? > > I'm not sure about this, the behavior of map() seems to have changed in > Python3, I just tried the following with Python2 first: > > $ python > Python 2.7.9 (default, Mar 1 2015, 12:57:24) > [GCC 4.9.2] on linux2 > Type "help", "copyright", "credits" or "license" for more information. >>>> l = ['a', 'b', 'c'] >>>> def test(x): > ... print(x) > ... >>>> map(test, l) > a > b > c > [None, None, None] >>>> > > and then with Python3: > > $ python3 > Python 3.4.2 (default, Oct 8 2014, 10:45:20) > [GCC 4.9.1] on linux > Type "help", "copyright", "credits" or "license" for more information. >>>> l = ['a', 'b', 'c'] >>>> def test(x): > ... print(x) > ... >>>> map(test, l) > <map object at 0x7fdfcc6342b0> >>>> > > Personally I hardly ever use map(), so I never noticed that. In fact this > change is actually documented, see > https://docs.python.org/3.0/whatsnew/3.0.html#views-and-iterators-instead-of-lists > : > > "map() and filter() return iterators. If you really need a list, a quick > fix is e.g. list(map(...)), but a better fix is often to use a list > comprehension (especially when the original code uses lambda), or > rewriting the code so it doesn’t need a list at all. Particularly tricky > is map() invoked for the side effects of the function; the correct > transformation is to use a regular for loop " > > Not sure what's the use of these map objects, in Python3 now you can call > the map object's __next__() method to iterate. > But for your purpose certainly the for loop is the way to go. > > Best regards > > Michael > > > .-.. .. ...- . .-.. --- -. --. .- -. -.. .--. .-. --- ... .--. . .-. > > Intuition, however illogical, is recognized as a command prerogative. > -- Kirk, "Obsession", stardate 3620.7 > _______________________________________________ > Tkinter-discuss mailing list > Tkinter-discuss@python.org > https://mail.python.org/mailman/listinfo/tkinter-discuss > _______________________________________________ Tkinter-discuss mailing list Tkinter-discuss@python.org https://mail.python.org/mailman/listinfo/tkinter-discuss
