On 12/06/2015 16:00, Fabien wrote:
Folks,I am developing a program which I'd like to be python 2 and 3 compatible. I am still relatively new to python and I use primarily py3 for development. Every once in a while I use a py2 interpreter to see if my tests pass through. I just spent several hours tracking down a bug which was related to the fact that zip is an iterator in py3 but not in py2. Of course I did not know about that difference. I've found the izip() function which should do what I want, but that awful bug made me wonder: is it a bad practice to interactively modify the list you are iterating over? I am computing mass fluxes along glacier branches ordered by hydrological order, i.e. branch i is guaranteed to flow in a branch later in that list. Branches are objects which have a pointer to the object they are flowing into. In pseudo code: for stuff, branch in zip(stuffs, branches): # compute flux ... # add to the downstream branch id_branch = branches.index(branch.flows_to) branches[id_branch].property.append(stuff_i_computed) So, all downstream branches in python2 where missing information from their tributaries. It is quite a dangerous code but I can't find a more elegant solution. Thanks! Fabien
Start here https://docs.python.org/3/howto/pyporting.html -- My fellow Pythonistas, ask not what our language can do for you, ask what you can do for our language. Mark Lawrence -- https://mail.python.org/mailman/listinfo/python-list
