Removes unicode 'u' response from "glance image-tag-update"

"glance image-tag-update" command returns unicoded response
for lists. Therefore it requires print_list method from util
class to handle such case. Added unicode_key_value_to_string()
method to remove extra 'u' from lists and dictionaries. This
fix is inspired from cinderclient's implementation.

Change-Id: I16a04e8d34f7629f72fe389456001ca1db9335ea
Closes-bug: #1534046

glanceclient/common/utils.py

@@ -177,6 +177,12 @@ def pretty_choice_list(l):
 
 
 def print_list(objs, fields, formatters=None, field_settings=None):
+    '''Prints a list of objects.
+
+    @param objs: Objects to print
+    @param fields: Fields on each object to be printed
+    @param formatters: Custom field formatters
+    '''
     formatters = formatters or {}
     field_settings = field_settings or {}
     pt = prettytable.PrettyTable([f for f in fields], caching=False)
@@ -196,11 +202,36 @@ def print_list(objs, fields, formatters=None, field_settings=None):
                 field_name = field.lower().replace(' ', '_')
                 data = getattr(o, field_name, None) or ''
                 row.append(data)
+        count = 0
+        # Converts unicode values in list to string
+        for part in row:
+            count = count + 1
+            if isinstance(part, list):
+                part = unicode_key_value_to_string(part)
+                row[count - 1] = part
         pt.add_row(row)
 
     print(encodeutils.safe_decode(pt.get_string()))
 
 
+def _encode(src):
+    """remove extra 'u' in PY2."""
+    if six.PY2 and isinstance(src, unicode):
+        return src.encode('utf-8')
+    return src
+
+
+def unicode_key_value_to_string(src):
+    """Recursively converts dictionary keys to strings."""
+    if isinstance(src, dict):
+        return dict((_encode(k),
+                    _encode(unicode_key_value_to_string(v)))
+                    for k, v in src.items())
+    if isinstance(src, list):
+        return [unicode_key_value_to_string(l) for l in src]
+    return _encode(src)
+
+
 def print_dict(d, max_column_width=80):
     pt = prettytable.PrettyTable(['Property', 'Value'], caching=False)
     pt.align = 'l'

glanceclient/tests/unit/test_utils.py

@@ -115,6 +115,42 @@ class TestUtils(testtools.TestCase):
 ''',
                          output_dict.getvalue())
 
+    def test_print_list_with_list_no_unicode(self):
+        class Struct(object):
+            def __init__(self, **entries):
+                self.__dict__.update(entries)
+
+        # test for removing 'u' from lists in print_list output
+        columns = ['ID', 'Tags']
+        images = [Struct(**{'id': 'b8e1c57e-907a-4239-aed8-0df8e54b8d2d',
+                  'tags': [u'Name1', u'Tag_123', u'veeeery long']})]
+        saved_stdout = sys.stdout
+        try:
+            sys.stdout = output_list = six.StringIO()
+            utils.print_list(images, columns)
+
+        finally:
+            sys.stdout = saved_stdout
+
+        self.assertEqual('''\
++--------------------------------------+--------------------------------------+
+| ID                                   | Tags                                 |
++--------------------------------------+--------------------------------------+
+| b8e1c57e-907a-4239-aed8-0df8e54b8d2d | ['Name1', 'Tag_123', 'veeeery long'] |
++--------------------------------------+--------------------------------------+
+''',
+                         output_list.getvalue())
+
+    def test_unicode_key_value_to_string(self):
+        src = {u'key': u'\u70fd\u7231\u5a77'}
+        expected = {'key': '\xe7\x83\xbd\xe7\x88\xb1\xe5\xa9\xb7'}
+        if six.PY2:
+            self.assertEqual(expected, utils.unicode_key_value_to_string(src))
+        else:
+            # u'xxxx' in PY3 is str, we will not get extra 'u' from cli
+            # output in PY3
+            self.assertEqual(src, utils.unicode_key_value_to_string(src))
+
     def test_schema_args_with_list_types(self):
         # NOTE(flaper87): Regression for bug
         # https://bugs.launchpad.net/python-glanceclient/+bug/1401032