On Fri, Oct 30, 2009 at 6:39 PM, Robert Lummis <robert.lum...@gmail.com> wrote: > I want to move some functions from my "main" program file to a module > file because the main file is getting too big for convenience. The > functions access arrays (lists of lists) that are defined and > initialised in the main file. How do I reference the main file arrays > from statements within the module file?
A couple of solutions: - Put the arrays into some kind of structure that you can pass as an argument. The structure could be a list, dict or custom class. - Create a class (or possibly more than one class) to hold both the data and the functions that operate on it. > With everything in the main file a function like the following works > as expected: > > def functionA (row, col, x): > grid[row][col] = <a value that depends on x and other values in grid> > > where grid[] is initialised outside of any functions (i.e. in the main). > > So how do I write that function when I move it to a module file? I That might make a good method of a grid class. Then it would become something like def functionA(self, row, col, x): self.grid[row][col] = ... > So how do I write that function when I move it to a module file? I > thought I read somewhere that the main routine has the name "__main__" > so I tried: > > __main__.grid[row][col] = <...> > > but that gives "NameError: name '__main__' is not defined". You can import __main__ and the above will work but that is *not* the best solution. > I understand that it is best to minimize cross-file references but I > feel it is warranted in this case. Cross-file references are not bad by themselves but circular references (module A uses module B and B uses A) are a bad idea. > Even if you think it isn't good > practice I would like to understand how to do it (or else why it can't > be done). Is there some other way to keep files from getting too big? Yes. Object-oriented design is the most common way of dealing with this. Think about decomposing your code into cooperating objects. Kent _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
