Quiece 'invalid escape sequence' deprecation msg

Glance tests are currently too verbose for subunit and make
them randomly fail under python 3.

Using raw strings should avoid the DeprecationWarnings around
'invalid escape sequence' being used with the re module.

Change-Id: I14c381ac4b17ca4c5755ed78c55dc44362ab37ef

glance/api/common.py

@@ -112,7 +112,7 @@ def get_remaining_quota(context, db_api, image_id=None):
 
     # set quota must have a number optionally followed by B, KB, MB,
     # GB or TB without any spaces in between
-    pattern = re.compile('^(\d+)((K|M|G|T)?B)?$')
+    pattern = re.compile(r'^(\d+)((K|M|G|T)?B)?$')
     match = pattern.match(users_quota)
 
     if not match:

glance/api/v2/images.py

@@ -676,7 +676,7 @@ class RequestDeserializer(wsgi.JSONRequestDeserializer):
         if not pointer.startswith('/'):
             msg = _('Pointer `%s` does not start with "/".') % pointer
             raise webob.exc.HTTPBadRequest(explanation=msg)
-        if re.search('/\s*?/', pointer[1:]):
+        if re.search(r'/\s*?/', pointer[1:]):
             msg = _('Pointer `%s` contains adjacent "/".') % pointer
             raise webob.exc.HTTPBadRequest(explanation=msg)
         if len(pointer) > 1 and pointer.endswith('/'):

glance/common/utils.py

@@ -516,7 +516,7 @@ def is_valid_hostname(hostname):
 
 def is_valid_fqdn(fqdn):
     """Verify whether a host is a valid FQDN."""
-    return re.match('^[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$', fqdn) is not None
+    return re.match(r'^[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$', fqdn) is not None
 
 
 def parse_valid_host_port(host_port):

glance/db/sqlalchemy/metadata.py

@@ -395,7 +395,7 @@ def _export_data_to_file(meta, path):
     namespace_table = get_metadef_namespaces_table(meta)
     namespaces = namespace_table.select().execute().fetchall()
 
-    pattern = re.compile('[\W_]+', re.UNICODE)
+    pattern = re.compile(r'[\W_]+', re.UNICODE)
 
     for id, namespace in enumerate(namespaces, start=1):
         namespace_id = namespace['id']