const_fold.py 文件源码

def visit_UnaryOp(self, node):
        if not self.config.constant_folding:
            return

        eval_unaryop = EVAL_UNARYOP.get(node.op.__class__)
        if eval_unaryop is None:
            return

        if isinstance(node.op, ast.Invert):
            types = int
        else:
            types =  COMPLEX_TYPES

        value = get_constant(node.operand, types=types)
        if value is not UNSET:
            result = eval_unaryop(value)
            return self.new_constant(node, result)

        if (isinstance(node.op, ast.Not)
        and isinstance(node.operand, ast.Compare)):
            new_node = self.not_compare(node)
            if new_node is not None:
                return new_node