Python: Changing a pre-defined variable inside if a function

Question

I'm working on a code for a 'casino' in Python (no GUI yet, just trying to get the codes down for now). I want coins to be a system of currency, and I have a perfectly fine Russian Roulette code. If the player survives, I want the code to add onto the player's coins. Said coins are already defined at the top of the code, outside of the function. When I try

return coins += 100

at the elif clause for the player's survival, I immediately get "invalid syntax" in IDLE. How can I have the function modify 'coins'?

coins are already defined at the top of the code, outside of the function this can be, but is usually not a good idea. — Tim
– Tim, Commented May 21, 2014 at 13:36
removed IDLE tag since this has nothing to do with using the IDE itself. — Wooble
– Wooble, Commented May 21, 2014 at 13:46

arshajii · Accepted Answer · 2014-05-21 13:34:34Z

2

Make sure that you're using coins as a global variable:

>>> coins = 0
>>> 
>>> def f():
...     global coins  # <--
...     coins += 100  # notice also that we're not returning anything
... 
>>> f()
>>> 
>>> coins
100

answered May 21, 2014 at 13:34

arshajii

130k26 gold badges246 silver badges293 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Hans · Accepted Answer · 2014-05-21 13:34:30Z

0

Try return 100 And the caller code would be like coins += russianRoulette() That should work

answered May 21, 2014 at 13:34

Hans

2,5323 gold badges29 silver badges36 bronze badges

1 Comment

glglgl Over a year ago

... if, e. g., russianRoulette() raises and exception on "deadly hit".

dawg · Accepted Answer · 2014-05-21 13:56:47Z

0

Use coins as a function parameter then return that value with the addition:

coins=2

def f(coins):
    return coins+100

>>> f(coins)  
102

Or just assign coins the value returned:

>>> coins=f(coins)
>>> coins
102
>>> coins=f(coins)
>>> coins
202

answered May 21, 2014 at 13:56

dawg

105k24 gold badges142 silver badges217 bronze badges

Collectives™ on Stack Overflow

Python: Changing a pre-defined variable inside if a function

3 Answers 3

Comments

1 Comment

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Related