Error: "global name '_' is not defined" during glance image-create

I am new to openstack. When i install openstack, there are lot of steps to follow for installation. In glance, i wants to download a pre‐bundled image for testing purpose. But when i give glance image-create command or
glance image-create --name Cirros --is-public true --container-format bare --disk-format qcow2 --location https://launchpad.net/cirros/trunt/0.3.0/download/cirros-0.3.0-x86_64-disk.img
i got this error global name '_' is not defined.

Please anyone can help me!!