On Mon, 05 Sep 2005 11:53:09 +0200, "Diez B. Roggisch" <[EMAIL PROTECTED]> wrote:
>> >> I seem to recall a post by Diez Roggish that reload() doesn't always >> work as it should. Any news on this? At least im my preliminary test it >> works. > >Read the docs on reload: > >http://www.python.org/doc/current/lib/built-in-funcs.html > >""" > >If a module is syntactically correct but its initialization fails, the >first import statement for it does not bind its name locally, but does >store a (partially initialized) module object in sys.modules. To reload >the module you must first import it again (this will bind the name to >the partially initialized module object) before you can reload() it. > >When a module is reloaded, its dictionary (containing the module's >global variables) is retained. Redefinitions of names will override the >old definitions, so this is generally not a problem. If the new version >of a module does not define a name that was defined by the old version, >the old definition remains. This feature can be used to the module's >advantage if it maintains a global table or cache of objects -- with a >try statement it can test for the table's presence and skip its >initialization if desired: > > >try: > cache >except NameError: > cache = {} > > >It is legal though generally not very useful to reload built-in or >dynamically loaded modules, except for sys, __main__ and __builtin__. >In many cases, however, extension modules are not designed to be >initialized more than once, and may fail in arbitrary ways when reloaded. > >If a module imports objects from another module using from ... import >..., calling reload() for the other module does not redefine the >objects imported from it -- one way around this is to re-execute the >from statement, another is to use import and qualified names >(module.name) instead. > >If a module instantiates instances of a class, reloading the module >that defines the class does not affect the method definitions of the >instances -- they continue to use the old class definition. The same is >true for derived classes. >""" > >So - expect strange things to happen, sometimes. > >I personally _never_ felt the need for reload - after all, writing more >than totally trivial crap on the commandline justifies a small >testscript - which I then just execute on the commandline. > >Diez What about something on the pattern of (untested!) import algomodule # first time def algoreload(): algosource = algomodule.__file__.replace('.pyc','py') algomodule.__dict__.clear() try: execfile(algosource, algomodule.__dict__) algomodule.__file__ = algosource return 'ok' except Exception, e: return '%s: %s -- couldn't execfile %r' %(e.__class__.__name__, e, algosource) while True: cmd = raw_input('cmd > ').strip() if cmd == 'reload': print algoreload() elif cmd == 'exit': raise SystemExit('ok, exiting ...') elif cmd == 'edit': print os.popen('notepad.exe '+algomodule.__file__.replace('.pyc','py')).read() or 'ok' else: cmd = cmd.split() args = map(float, cmd[1:]) print getattr(algomodule, cmd[0], (lambda name, *ign: 'No such function: %r'%name).__get__(cmd[0], str))(*args) this would (theoretically ;-) let you type commands like sqrt 9 and have alogomodule.sqrt called with float('9'), and then edit and edit the module source in notepad, and then sqrt 16 and have the new function called, etc. The cmd module will let you set up something fancier than above, and obviously you don't have to run notepad ;-) Regards, Bengt Richter -- http://mail.python.org/mailman/listinfo/python-list
