So quick analysis... You're making text parser which works as following:
- Get first word of "command", if we don't know word user used invalid input -> inform and restart
- If user used known "command", parse its arguments (like:
go north, go south) and let "nested" function take care of argument
Note that "main parsing function" doesn't need to know whether arguments for go() are valid, it just delegates responsibility for validation to go().
So I think you should build code (class) like this:
class Game:
# Initialize internal variables, method automatically called on g = Game()
def __init__(self):
self._exit = False
# Array of known commands, used in run, basically maps commands
# to function and it says: if will get 'go' execute self._go
self._commands = {
'go': self._go,
'quit': self._quit
}
# Array of go sub commands, used by _go
self._commands_go = {
'north': self._go_north
# ...
}
# Mathod for parsing command, if it gets "comamnd" returns ("command",None)
# if "command arg1 arg2" returns ("command", "arg1 arg2")
@staticmethod
def parse_command(string):
string = str(string)
index = string.find(' ')
if index < 0:
return (string, None)
return (string[:index], string[index+1:])
# This is main method; the only one which should be called from outside
# It will just read data from input in never ending loop and parse commands
def run(self):
while not self._exit:
src = input('> ')
(command,args) = Game.parse_command( src)
# Do we have this command, execute it
if command in self._commands:
self._commands[command](args)
else:
print( 'I\'m sorry I don\'t known command {}, try one of these:'.format(command))
print( '\n'.join( self._commands.keys()))
#######################################################
# All game commands go here
#######################################################
def _quit(self,args):
self._exit = True
print( 'Bye bye')
# Movement handling, will get executed when user types 'go ...' nad '...' will be in arg
def _go(self,args):
# No argument
if args is None:
print( 'Go excepts one of these:', '; '.join( self._commands_go.keys()))
return False
# Split sub command anr arguments
(command,args) = Game.parse_command(args)
if command not in self._commands_go:
print( 'Go excepts one of these:', '; '.join( self._commands_go.keys()))
return False
if args is not None:
print( 'Too many arguments for go')
return False
self._commands_go[command](args)
return True
# Go north
def _go_north(self, args):
print( 'Going north')
game = Game()
game.run()
Which would allow you to:
- build complex nested commands
- build nice and readable commands hierarchy (
inventory item 123 update use potion 345) instead of hardly readable set of complex conditions
- build function aliases
go north can be aliased as gn by adding 'gn': self._go_north to _commands
- build reusable arguments parsing
(item_id, action, args) = self._parse_item_action(args)
- take advantages of object oriented programming (no global variables, everything will be class attribute, lower risk of accidental variables overwriting)
And if you need to parse goasdf as go you can just simply:
for i in self._commands:
if input.startswirh( i):
return self._commands[i](...)
print('Invalid command')
return False
Note: I haven't tested the code, it's just out of my head.