def is_sortable_import()

in usort/sorting.py [0:0]

• 32 lines of code
• 15 McCabe index (conditional complexity)

    def is_sortable_import(self, stmt: cst.CSTNode) -> bool:
        """
        Determine if any individual statement is sortable or should be a barrier.

        Handles skip directives, configured side effect modules, and star imports.
        """
        if isinstance(stmt, cst.SimpleStatementLine):
            # from foo import (
            #     bar,
            # )  # usort:skip
            comment = stmt.trailing_whitespace.comment
            if self.has_skip_comment(comment):
                return False

            # N.b. `body` is a list, because the SimpleStatementLine might have
            # semicolons.  We only look at the first, which is probably the most
            # dangerous thing in here.
            #
            # If black is run, it will put the semicolon pieces on different lines,
            # but we don't want to do that until we reflow and handle directives
            # like noqa.  TODO do that before calling is_sortable_import, and assert
            # that it's not a compound statement line.
            if isinstance(stmt.body[0], cst.ImportFrom):
                # from foo import (  # usort:skip
                #     bar,
                # )
                if isinstance(stmt.body[0].lpar, cst.LeftParen) and isinstance(
                    stmt.body[0].lpar.whitespace_after, cst.ParenthesizedWhitespace
                ):
                    comment = stmt.body[0].lpar.whitespace_after.first_line.comment
                    if self.has_skip_comment(comment):
                        return False
                # `from x import *` is a barrier
                if isinstance(stmt.body[0].names, cst.ImportStar):
                    return False
                # check for side effect modules, but ignore local (from .) imports (TODO?)
                elif stmt.body[0].module is not None:
                    base = cst.helpers.get_full_name_for_node_or_raise(
                        stmt.body[0].module
                    )
                    names = [name.evaluated_name for name in stmt.body[0].names]
                    if self.config.is_side_effect_import(base, names):
                        return False
                return True
            elif isinstance(stmt.body[0], cst.Import):
                base = ""
                names = [name.evaluated_name for name in stmt.body[0].names]
                if self.config.is_side_effect_import(base, names):
                    return False
                return True
            else:
                return False
        else:
            return False