Python switch the output based on input

Question

Can we write the following code in one line, when a function switch the current player another one?

    def switch_user(self,current):
       if self.current == 'Player-1':
              self.current = 'Player-2'
      elif self.current == 'Player-2':
           self.current = 'Player-1'
    return

See [Replacements for switch statement in Python?](http://stackoverflow.com/questions/60208/replacements-for-switch-statement-in-python) — e0k, Dec 17 '16 at 06:57
@e0k While that would work, it sounds like this question isn't really asking about equivalents for a `switch` statement - the use of the word "switch" is coincidental. It seems to be asking how to concisely toggle between two values. — David Z, Dec 17 '16 at 07:12
@DavidZ Good point. The code looks similar to a switch statement because it is making multiple comparisons against the same value. That must have distracted me. The word "switch" in the question only refers to switching players. — e0k, Dec 17 '16 at 07:22

score 2 · Accepted Answer · answered Dec 17 '16 at 06:56

2

self.current = 'Player-2' if self.current == 'Player-1' else 'Player-1'

answered Dec 17 '16 at 06:56

Amber

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shouldn't that be `current == 'Player-1'` instead of `self.current == 'Player-1'`? – Mohammad Yusuf Dec 17 '16 at 07:09
@MohammadYusufGhazi `current` would make more sense (otherwise you're not using the argument), but then the example in the question is also incorrect. – e0k Dec 17 '16 at 07:24
I am using self because 'current' is a global variable, with self.current it becomes local. – EveryProblemHasSolution Dec 17 '16 at 18:00

Nath · Answer 2 · 2016-12-17T12:03:18.300

To make things expandable to multiple players I'd use cycle from the itertools standard library https://docs.python.org/2/library/itertools.html#itertools.cycle

from itertools import cycle      

players_cycle = cycle(['Player-1', 'Player-2'])

current = players_cycle()

This way you are able add a third player or make the player objects more complex over time Without having to redo the switch function.

Python switch the output based on input

2 Answers2