Reserved names

[Karrion]

So I made a fresh project, wrote a few lines and got this error when clicking launch project:

I'm sorry, but an uncaught exception occurred.

After initialization, but before game start.
File "game/screens.rpy", line 716, in prepare_screen
screen preferences():
File "game/screens.rpy", line 716, in prepare
screen preferences():
File "game/screens.rpy", line 720, in prepare
use game_menu(_("Preferences"), scroll="viewport"):
File "game/screens.rpy", line 720, in prepare
use game_menu(_("Preferences"), scroll="viewport"):
File "game/screens.rpy", line 722, in prepare
vbox:
File "game/screens.rpy", line 722, in prepare
vbox:
File "game/screens.rpy", line 754, in prepare
hbox:
File "game/screens.rpy", line 754, in prepare
hbox:
File "game/screens.rpy", line 768, in prepare
vbox:
File "game/screens.rpy", line 768, in prepare
vbox:
File "game/screens.rpy", line 770, in prepare
if config.has_music:
File "game/screens.rpy", line 770, in prepare
if config.has_music:
File "game/screens.rpy", line 773, in prepare
hbox:
File "game/screens.rpy", line 773, in prepare
hbox:
File "game/screens.rpy", line 774, in prepare
bar value Preference("music volume")
File "game/screens.rpy", line 774, in prepare
bar value Preference("music volume")
File "renpy/common/00preferences.rpy", line 470, in Preference
rv = get()
File "renpy/common/00preferences.rpy", line 440, in get
if len(n) == 3 and n[0] == "mixer":
Exception: Character expects its what argument to be a string, got [u'music', u'volume'].

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

Full traceback:
File "C:\Users\karri\Downloads\renpy-7.1.0-sdk\renpy\bootstrap.py", line 313, in bootstrap
renpy.main.main()
File "C:\Users\karri\Downloads\renpy-7.1.0-sdk\renpy\main.py", line 520, in main
run(restart)
File "C:\Users\karri\Downloads\renpy-7.1.0-sdk\renpy\main.py", line 90, in run
renpy.display.screen.prepare_screens()
File "C:\Users\karri\Downloads\renpy-7.1.0-sdk\renpy\display\screen.py", line 909, in prepare_screens
s.ast.prepare_screen()
File "game/screens.rpy", line 716, in prepare_screen
screen preferences():
File "game/screens.rpy", line 716, in prepare
screen preferences():
File "game/screens.rpy", line 720, in prepare
use game_menu(_("Preferences"), scroll="viewport"):
File "game/screens.rpy", line 720, in prepare
use game_menu(_("Preferences"), scroll="viewport"):
File "game/screens.rpy", line 722, in prepare
vbox:
File "game/screens.rpy", line 722, in prepare
vbox:
File "game/screens.rpy", line 754, in prepare
hbox:
File "game/screens.rpy", line 754, in prepare
hbox:
File "game/screens.rpy", line 768, in prepare
vbox:
File "game/screens.rpy", line 768, in prepare
vbox:
File "game/screens.rpy", line 770, in prepare
if config.has_music:
File "game/screens.rpy", line 770, in prepare
if config.has_music:
File "game/screens.rpy", line 773, in prepare
hbox:
File "game/screens.rpy", line 773, in prepare
hbox:
File "game/screens.rpy", line 774, in prepare
bar value Preference("music volume")
File "game/screens.rpy", line 774, in prepare
bar value Preference("music volume")
File "C:\Users\karri\Downloads\renpy-7.1.0-sdk\renpy\python.py", line 1953, in py_eval_bytecode
return eval(bytecode, globals, locals)
File "<screen language>", line 774, in <module>
File "renpy/common/00preferences.rpy", line 470, in Preference
rv = get()
File "renpy/common/00preferences.rpy", line 440, in get
if len(n) == 3 and n[0] == "mixer":
File "C:\Users\karri\Downloads\renpy-7.1.0-sdk\renpy\character.py", line 1043, in __call__
raise Exception("Character expects its what argument to be a string, got %r." % (what,))
Exception: Character expects its what argument to be a string, got [u'music', u'volume'].

Windows-8-6.2.9200
Ren'Py 7.1.4.1266
Marine Express Satsujin Jiken 1.0
Tue Feb 19 20:27:53 2019

It seems that one of the character definitions is redirecting to a music parameter. Are there any reserved variables that I should know of?

These are my definitions:

define ran = Character("Ranko")
define ast = Character("Astrid")
define eri = Character("Erica")
define ire = Character("Irene")
define jes = Character("Jessica")
define fra = Character("Frank")
define law = Character("Lawrence")
define len = Character("Lena")
define cla = Character("Clarisse")
define gat = Character("Gatas")
define cat = Character("Catherine")
define mao = Character("Mao")
define kat = Character("Katya")
define spi = Character("Spike")
define mad = Character("Maddy")

Thanks in advance.

[strayerror]

I suspect that at least len may be problematic, as it's a commonly used top-level function in python. I'd expect redefining like this it to give you some grief.

[Alex]

You will find them here - https://www.renpy.org/doc/html/reserved.html#