__init__.py 文件源码

def visit_Slice(self, node):
        """
        Slice(expr? lower, expr? upper, expr? step)
        """
        if node.lower and node.upper and node.step:
            """ <Python> [8, 9, 10, 11, 12, 13, 14][1:6:2]
                <Ruby>   [8, 9, 10, 11, 12, 13, 14][1...6].each_slice(2).map(&:first) """
            return "%s...%s,each_slice(%s).map(&:first)" % (self.visit(node.lower),
                    self.visit(node.upper), self.visit(node.step))
        if node.lower and node.upper:
            return "%s...%s" % (self.visit(node.lower),
                    self.visit(node.upper))
        if node.upper and not node.step:
            return "0...%s" % (self.visit(node.upper))
        if node.lower and not node.step:
            return "%s..-1" % (self.visit(node.lower))
        if not node.lower and not node.upper and not node.step:
            return "0..-1"
        raise NotImplementedError("Slice")