En Tue, 23 Oct 2007 23:34:38 -0300, BBands <[EMAIL PROTECTED]> escribió:
> On Oct 23, 4:20 pm, [EMAIL PROTECTED] wrote: > I was trying to understand why it worked when written in, but not when > included. Not *included*. When you do `import doStuff` you dont "include" anything; this is what happens (simplified): - Look into the already loaded modules; if a "doStuff" module already exists, return it. - Search some directories on disk, looking for "doStuff.py". If found, load and execute it (remember that import, class, def, etc. are *executable* statements in Python). - If still not found, raise an error. So, after successful execution of `import doStuff`, you have a new name `doStuff` that refers to the imported module. It's not the "contents" of doStuff that gets "included" into the current module; doStuff exists by itself as a separate module, and you get a name that refers to it. >> I think the right solution would be not to use 'a' as a global >> variable, but rather to pass it as an explicit parameter to the >> function. > > Does doing this make a copy of a? No! Python never makes a copy unless you explicitely say so. >> In module doStuff: >> >> def doStuff(a): >> # some calcs >> a.b = 0 >> >> In the main module: >> >> import doStuff >> # ... >> doStuff.doStuff(a) > > In my real ap a is quite large... It doesn't matter. `a` is just a name, referencing an object. It's never "copied" unless you specifically ask for it. Passing objects as arguments is absolutely common, and the right thing to do in this case; it's efficient, don't worry... -- Gabriel Genellina -- http://mail.python.org/mailman/listinfo/python-list
