Modify some codes in order to lead them meet the python3 common pattern.
Look through the following patterns of Cinder,
      map() and filter() if a list is needed on Python 3:
          Replace map(func, data) with [func(item) for item in data]
          Replace filter(lambda obj: test(obj), data) with
             [obj for obj in data if test(obj)]
      Replace exceptions.OSError with OSError and
         remove "import exceptions"
      Replace iterator.next() with next(iterator)
      Replace basestring with six.string_types
      Replace unicode with six.text_type
      Replace (str, unicode) with six.string_types
      Replace "for key in dict.iterkeys()" with "for key in dict"
      Replace dict.iteritems() with dict.items()
      Replace dict.itervalues() with dict.values()
I found that only "filter(lambda obj: test(obj), data)" and
"map(func, data)"need to modify.
The other items are not be founded in Cinder.

Reference:https://wiki.openstack.org/wiki/Python3#Common_patterns

Change-Id: If33ec39eb176c14086132d3099c6ec577f956ded

If there is an exception raised by cinder-api while using
--profile option, the trace ID is not printed. Moving the
trace ID print statement to finally block to fix this.

Change-Id: I03df8cd47185d148051d66396f6cd8118efff73c
Closes-bug: #1642888

Currently the dest of the deprecated --endpoint-type arg
is 'endpoint_type'. However, the code only uses 'os_endpoint_type'
so right now it isn't being used at all. This patch updates
the dest to be 'os_endpoint_type' so that the variable can
be assigned correctly.

Change-Id: Ie8592d12bcf95e4ccff571e831440b18f5acfd40
Closes-bug: #1454436

Help msg and output info should support il8n.
And delete the unused import six.

Close-Bug: #1629157
Change-Id: Ie1faf0a83ec5f04dc6c8303f1ea0c931ba482e2a

If the cinder shell is run in debug mode
(CINDERCLIENT_DEBUG is set in the environment or
with --debug), print a traceback for unhandled
exceptions.

This makes it possible to debug issues like this:
  $ cinder credentials
  ERROR: list indices must be integers, not str

Related-Bug: #1631142

Co-Authored-By: Gorka Eguileor <geguileo@redhat.com>
Change-Id: I5e9b3283602d404ab43494f15d57ec5abbcd77dc

In shell.py, six is imported twice.
In this patchset, one of them is removed.

TrivialFix

Change-Id: Ifbf6dcb20d5de54855aab53538b57eb11185ab2b

Our current APIVersion object has an is_null method to check when the
version instance is null (major=0 and minor=0).

While this works it is not very pythonic, since you have to write
expressions such as:

 if not min_version and not max_version:
     return True
 elif ((min_version and max_version) and
       max_version.is_null() and min_version.is_null()):
     return True

This patch removes the is_null method and instead implements the truth
value testing to simplify expressions and make code more pythonic.

So previous code would just look like:

 if not min_version and not max_version:
     return True

Because this will work with min_version being None or being an
APIVersion instance with major=0 and minor=0.

Change-Id: I7497c5dc940c1e726507117cadbad232d8c1d80d

Now, "cinder help subcommand" can not show whether an argument
is supported for a specific microversion.
With this change, developers only need to add a start_version or
end_version in the utils.arg wrap, cinderclient will support
the microversion for that arguement.

    @utils.arg(
    '--foo',
    start_version='3.1')
    @utils.arg(
    '--bar',
    start_version='3.2',
    end_version='3.5')
    def do_some_action():
        ......

In previous example, an exception will be raised for such command:
   $ cinder --os-volume-api-version 3.6 --bar some-ation

And only "--foo" will show up for such help command:
   $ cinder --os-volume-api-version 3.1 help some-ation

Change-Id: I74137486992846bbf9fdff53c009851db2356eef
Partial-Bug: #1600567
Co-Authored-By: Nate Potter <nathaniel.potter@intel.com>

'six' is an independent third party module so it doesn't
need to be imported and used from oslo_utils.strutils.

TrivialFix

Change-Id: Icb3232bb1ebae0e8332e66c5806474d7f9dfd6df

Currently with '--debug' option any cinder command only logs the
request from keystoneauth and not the main cinder service request.

Added keystoneauth logger to self.ks_logger so that logs can be
logged as expected.

Closes-Bug: #1606814

Change-Id: I7193aa6f43cb3186c49fc409b6e1ce7a36f596f9