It would be bad if we were calling `PySequence_Check` here -- it is entirely possible for an object to return true to `PySequence_Check`, and still have magic numpy attributes.

But we aren't calling `PySequence_Check`, we're explicitly checking for exact instances of the standard built-in sequence types. These can't possibly have magic numpy attributes, so the current code looks correct to me. Possibly a little over-eager (who passes a dict to functions that are expecting an array-like?), which tends to defeat the purpose of the optimization, but `CheckExact` macros are so fast (one pointer comparison) that it probably doesn't matter too much if we're a little over-eager about them.