Chris Rebert <[email protected]> writes: > On Tue, May 5, 2009 at 8:52 AM, George Oliver <[email protected]> > wrote: >> hi, I'm a Python beginner with a basic question. I'm writing a game >> where I have keyboard input handling defined in one class, and >> command execution defined in another class. The keyboard handler >> class contains a dictionary that maps a key to a command string (like >> 'h': 'left') and the command handler class contains functions that do >> the commands (like def do_right(self):), >> >> I create instances of these classes in a list attached to a third, >> 'brain' class. What I'd like to have happen is when the player >> presses a key, the command string is passed to the command handler, >> which runs the function. However I can't figure out a good way to >> make this happen. >> >> I've tried a dictionary mapping command strings to functions in the >> command handler class, but those dictionary values are evaluated just >> once when the class is instantiated. I can create a dictionary in a >> separate function in the command handler (like a do_command function) >> but creating what could be a big dictionary for each input seems kind >> of silly (unless I'm misunderstanding something there). >> >> What would be a good way to make this happen, or is there a different >> kind of architecture I should be thinking of? > > You could exploit Python's dynamism by using the getattr() function: > > key2cmd = {'h':'left'} > cmd_name = key2cmd[keystroke] > getattr("do_"+cmd_name, cmd_handler)() #same as cmd_handler.do_left()
getattr(cmd_handler, "do_" + cmd_name)() will work even better! -- Arnaud -- http://mail.python.org/mailman/listinfo/python-list
