include tuples in b018 useless-statement check

[r-downing]

I was looking for something to detect useless tuple statements, noticed this had a useless-statement check but didn't include tuples. Any reason for that? Otherwise, figured we could add it?

[cooperlees]

Read again this morning and still confused at some of the test results ... I feel I'm missing something - Can you explain my missing context please :)

[cooperlees]

Why do we not need 34 here when we include 32 for modules tests? What am I missing here, cause the variable assign happens in a function it's fine?

[r-downing]

Oh it's a little confusing because the line numbers for the three different test cases are referring to the 3 different b018_....py files (but the line numbers are almost the same for 2 of the files). Added the same 3 lines to each of the files and corresponding test cases, in all cases the first 2 lines are bad and the 3rd is good

    (1,)  # bad
    (2, 3)  # bad
    t = (4, 5)  # good

[r-downing]

Something else to note here - a dangling comma after a single thing (e.g. a function call) will turn it into a tuple, which would get flagged as a useless statement:

print("abc")  # this is fine

print("abc"),  # the comma essentially makes this a tuple (None,) so this would be flagged as a useless expression.

^ wondering if this might be confusing and should be labelled a little differently? Or even as separate error? E.g. useless tuple expression - suggest removing the comma

[cooperlees]

Ok, I get it now. Yeah, I like maybe adding the "Do you have a trailing comma" at least in the README should help some lost people ...