Re: Local variable referenced before assignment [SOLVED]

[HotMango]

I have an inventory system with mixing function.
When I select two items for the mixing process and click on "Start mixing" a function is called (MixItems)which checks if there is any combination between the two.
If there is, then a new item is added to the inventory while both used items are removed .
But I also want to reset variables that define which item is selected as "mix1", "mix2", selected_item
Check this:

Code: Select all

init python:
    class Item:
        def __init__(self, name, img, hover_img):
            self.name = name
            self.img = img
            self.hover_img = hover_img



    def addItem(theitem):
        inventory.append(theitem)

    def MixItems():
        if mix1 == iScissors:
            if mix2 == iHair:
                inventory.append(iEye)
                inventory.remove(iHair)
                inventory.remove(iScissors)
                mix1 = None
                mix2 = None
                selected_item = None


    def MInv():
        mix1 = None
        mix2 = None
        selected_item = None

I get an error:

Code: Select all

I'm sorry, but an uncaught exception occurred.

While running game code:
  File "game/script.rpy", line 52, in script
    "Halo"
  File "renpy/common/00action_other.rpy", line 537, in __call__
    rv = self.callable(*self.args, **self.kwargs)
  File "game/inventory_screen.rpy", line 20, in MixItems
    if mix1 == iScissors:
UnboundLocalError: local variable 'mix1' referenced before assignment

-- Full Traceback ------------------------------------------------------------

Full traceback:
  File "game/script.rpy", line 52, in script
    "Halo"
  File "C:\Users\Business laptop\Downloads\Programs\renpy-7.3.5-sdk\renpy\ast.py", line 708, in execute
    renpy.exports.say(who, what, *args, **kwargs)
  File "C:\Users\Business laptop\Downloads\Programs\renpy-7.3.5-sdk\renpy\exports.py", line 1345, in say
    who(what, *args, **kwargs)
  File "C:\Users\Business laptop\Downloads\Programs\renpy-7.3.5-sdk\renpy\character.py", line 1142, in __call__
    self.do_display(who, what, cb_args=self.cb_args, **display_args)
  File "C:\Users\Business laptop\Downloads\Programs\renpy-7.3.5-sdk\renpy\character.py", line 842, in do_display
    **display_args)
  File "C:\Users\Business laptop\Downloads\Programs\renpy-7.3.5-sdk\renpy\character.py", line 591, in display_say
    rv = renpy.ui.interact(mouse='say', type=type, roll_forward=roll_forward)
  File "C:\Users\Business laptop\Downloads\Programs\renpy-7.3.5-sdk\renpy\ui.py", line 297, in interact
    rv = renpy.game.interface.interact(roll_forward=roll_forward, **kwargs)
  File "C:\Users\Business laptop\Downloads\Programs\renpy-7.3.5-sdk\renpy\display\core.py", line 2702, in interact
    repeat, rv = self.interact_core(preloads=preloads, trans_pause=trans_pause, **kwargs)
  File "C:\Users\Business laptop\Downloads\Programs\renpy-7.3.5-sdk\renpy\display\core.py", line 3518, in interact_core
    rv = root_widget.event(ev, x, y, 0)
  File "C:\Users\Business laptop\Downloads\Programs\renpy-7.3.5-sdk\renpy\display\layout.py", line 998, in event
    rv = i.event(ev, x - xo, y - yo, cst)
  File "C:\Users\Business laptop\Downloads\Programs\renpy-7.3.5-sdk\renpy\display\layout.py", line 998, in event
    rv = i.event(ev, x - xo, y - yo, cst)
  File "C:\Users\Business laptop\Downloads\Programs\renpy-7.3.5-sdk\renpy\display\layout.py", line 998, in event
    rv = i.event(ev, x - xo, y - yo, cst)
  File "C:\Users\Business laptop\Downloads\Programs\renpy-7.3.5-sdk\renpy\display\screen.py", line 714, in event
    rv = self.child.event(ev, x, y, st)
  File "C:\Users\Business laptop\Downloads\Programs\renpy-7.3.5-sdk\renpy\display\layout.py", line 998, in event
    rv = i.event(ev, x - xo, y - yo, cst)
  File "C:\Users\Business laptop\Downloads\Programs\renpy-7.3.5-sdk\renpy\display\layout.py", line 998, in event
    rv = i.event(ev, x - xo, y - yo, cst)
  File "C:\Users\Business laptop\Downloads\Programs\renpy-7.3.5-sdk\renpy\display\layout.py", line 998, in event
    rv = i.event(ev, x - xo, y - yo, cst)
  File "C:\Users\Business laptop\Downloads\Programs\renpy-7.3.5-sdk\renpy\display\layout.py", line 244, in event
    rv = d.event(ev, x - xo, y - yo, st)
  File "C:\Users\Business laptop\Downloads\Programs\renpy-7.3.5-sdk\renpy\display\layout.py", line 998, in event
    rv = i.event(ev, x - xo, y - yo, cst)
  File "C:\Users\Business laptop\Downloads\Programs\renpy-7.3.5-sdk\renpy\display\behavior.py", line 962, in event
    return handle_click(self.clicked)
  File "C:\Users\Business laptop\Downloads\Programs\renpy-7.3.5-sdk\renpy\display\behavior.py", line 897, in handle_click
    rv = run(action)
  File "C:\Users\Business laptop\Downloads\Programs\renpy-7.3.5-sdk\renpy\display\behavior.py", line 313, in run
    new_rv = run(i, *args, **kwargs)
  File "C:\Users\Business laptop\Downloads\Programs\renpy-7.3.5-sdk\renpy\display\behavior.py", line 320, in run
    return action(*args, **kwargs)
  File "renpy/common/00action_other.rpy", line 537, in __call__
    rv = self.callable(*self.args, **self.kwargs)
  File "game/inventory_screen.rpy", line 20, in MixItems
    if mix1 == iScissors:
UnboundLocalError: local variable 'mix1' referenced before assignment

Windows-8-6.2.9200
Ren'Py 7.3.5.606
inventory tst 5 1.0
Wed Jan 22 13:05:44 2020

When I change the MixItem() function to something like:

Code: Select all

    def MixItems():
        if mix1 == iScissors:
            if mix2 == iHair:
                inventory.append(iEye)
                inventory.remove(iHair)
                inventory.remove(iScissors)
                MInv
    def MInv():
      mix1 = None
      mix2 = None
      selected_item = None

No items are deselected.
I appreciate any help.

[RicharDann]

If you want different functions to affect the same variables, you'll want to make them global instead of local, by creating them with default statement.

Code: Select all

# initialize/create the variables
default mix1 = None
default mix2 = None
default selected_item = None

init python:

    def MixItems():
        global mix1, mix2, selected_item #import the variables so the function can check and change them
        if mix1 == iScissors:
            if mix2 == iHair:
                inventory.append(iEye)
                inventory.remove(iHair)
                inventory.remove(iScissors)
                mix1 = None
                mix2 = None
                selected_item = None

[HotMango]

Thank you so much! This worked!
BTW, I had to add "global bla bla bla" to every function.
Another thing: What is the difference between local and global variable? and from what I understand, you make global variables by defining them using "default" statement, but then what is the point of using "global" statement?
Thanks again!

[trooper6]

You do make variables global by using the default statement, the problem comes with the functions. Functions will create brand new local variables by default. If you want the function to use one of your global variables you've already defined rather than create a local one, you have to tell it by saying "Hey! global mix1, mix2!"

[HotMango]

Now I understand!
Thank you both for your help, much appreciated!