a tuple in python (in a code block) is defined by the commas; the parentheses are not mandatory (in the cases below). so these three are all equivalent:
a, b = 1, 2
a, b = (1, 2)
(a, b) = 1, 2
if i define a function
def f(a, b):
print(a, b)
calling it this way will work:
f(2, 3)
this will not:
f((2, 3))
# TypeError: f() missing 1 required positional argument: 'b'
how does python treat tuples differently when they are function arguments? here the parentheses are necessary (i understand why this is the case and i am happy python works this way!).
my question is: how does python treat tuples differently when they are function arguments.
For convenience, Python constructs a temporary tuple as needed for an assignment statement. Thus, all three of your assignment statements are exactly the same once they reach data movement.
A function call is not an assignment statement; it's a reference mapping. Therefore, the semantics are different.
If you want Python to unpack your tuple into two separate arguments, use the * operator:
f(*(2, 3))