def list_function(x):
return x[1] += 3
I want to do this, but apparently I can't. I understand I can do this
x[1] += 3
return x
but, I wanted to keep it on a single line. Does return always need to be on its own line, and if not, why does it need to be in this particular case?
You can have an arbitrary expression after the return statement, i.e. something that yields a value to be returned. Assignment, including augmented assignments like x[1] += 3, are not expressions in Python. They are statements, and as such don't yield a value, so they can't be used after return.
If you insist on having everything on a single line, you can of course write
x[1] += 3; return x
However, I can't see any valid reason to do so.
From documentation -
return_stmt ::= "return" [expression_list]
The return statement can only be followed by expressions. expression_list is -
expression_list ::= expression ( "," expression )* [","]
But x[1] += 1 is an augmented assignment statement , and as such you cannot have that after return .
x[1] += 3is not an expression, it's a complete statement and thus belongs to its own linereturn (x[1] += 3). Thanks for the help!return x[1] += 3;is valid C code, but it's equivalent tox[1] += 3; return x[1];.