On 3/31/17, Steven D'Aprano <[email protected]> wrote: > On Thu, Mar 30, 2017 at 04:23:05PM +0200, Pavol Lisy wrote: >> On 3/30/17, Nick Coghlan <[email protected]> wrote: >> > On 30 March 2017 at 19:18, Markus Meskanen <[email protected]> >> > wrote: >> >> Hi Pythonistas, >> >> >> >> yet again today I ended up writing: >> >> >> >> d = [[0] * 5 for _ in range(10)] >> >> d = [[0]*5]*10 # what about this? > > That doesn't do what you want. > > It's actually a common "gotcha", since it makes ten repetitions of the > same five element list, not ten *copies*.
Yes. It is clear that I did mistake here (sorry for that!). >> Simplified repeating could be probably useful in interactive mode. > I'm sorry, did you just suggest that language features should behave > differently in interactive mode than non-interactive mode? No. I did not suggest it. In contrary: if it is really useful for interactive python (*) then I suggest to implement it generally! (*) - this is matter of discussion where I don't think this proposal will be accepted... Python is multipurpose language which means that something which is not useful in A may be useful in B. Interactive python could be something like discussing with computer where we don't like to talk too much to say a little. > The point of interactive mode is to try > out syntax and code and see what it does, before using it in non- > interactive scripts. If things behave differently, people will be left > confused why the *exact same line of code* works differently in a script > and when they try it interactively. Sorry, this is not true. Not everybody use interactive python only for testing python constructs. (For example see http://ipython.readthedocs.io/en/stable/interactive/shell.html?highlight=shell ) PL _______________________________________________ Python-ideas mailing list [email protected] https://mail.python.org/mailman/listinfo/python-ideas Code of Conduct: http://python.org/psf/codeofconduct/
