pep8 returns false N302 for missing import

[Joe Gordon]

The pep8 for patch set 6 of https://review.openstack.org/#/c/22707 returned invalid results. http://logs.openstack.org/22707/6/check/gate-nova-pep8/21479/console.html.gz

pep8 reported
'./nova/virt/vmwareapi/vim.py:32:1: N302 import only modules.'from nova.virt.vmwareapi import error_util' does not import a module'

 because https://review.openstack.org/#/c/22707/6..7/nova/openstack/common/db/exception.py
 had in invalid import.

The current logic compares the last word of the module name along with the last word of the exception msg, and if they are not the same a module is missing. This check should also make sure the words "cannot import" aren't in the exception msg.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/22947

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/22947
Committed: http://github.com/openstack/nova/commit/99308d4dd3b16e00af4e610be4f07c7d99e49846
Submitter: Jenkins
Branch: master

commit 99308d4dd3b16e00af4e610be4f07c7d99e49846
Author: Joe Gordon <email address hidden>
Date: Mon Feb 25 19:44:29 2013 -0800

    Fix hacking.py to handle 'cannot import x'

    Fix missingImport logic to handle a module that cannot be imported, due
    to a missing dependant module.

    Due to the nature of this bug doctests cannot cover it.

    Fix bug 1133103

    Change-Id: Ia067bacc125b67e2d9e0cfc72495e4f13a8648ad