Uncanny line of code in Torchat source file

[buran]

config_defaults is a dict that has tuples as keys.
And in this line value = config_defaults[section, option] section, option part is implicit tuple, so it's a valid code, effectively the same as value = config_defaults[(section, option)].

from the docs:

output tuples are always enclosed in parentheses, so that nested tuples are interpreted correctly; they may be input with or without surrounding parentheses, although often parentheses are necessary anyway (if the tuple is part of a larger expression).

>>> foo = 'spam', 'eggs'
>>> foo
('spam', 'eggs')
>>> type(foo)
<class 'tuple'>
>>> 

also, another example:

some_dict = {(1, 2):'one',
             (3, 4):'two'}
print(some_dict[1, 2])