PEP8 remove direct type comparisons

Fixes bug #910763

According to PEP8,
- Object type comparisons should always use isinstance() instead
      of comparing types directly.

        Yes: if isinstance(obj, int):

        No: if type(obj) is type(1):

      When checking if an object is a string, keep in mind that it might be a
      unicode string too! In Python 2.3, str and unicode have a common base
      class, basestring, so you can do:

        if isinstance(obj, basestring):

Change-Id: I7c0fdecf99872f5b8f72b2c2ed4f5c539c33def1

bin/nova-manage

@@ -1084,7 +1084,7 @@ class ServiceCommands(object):
                      {"method": "show_host_resources",
                       "args": {"host": host}})
 
-        if type(result) != dict:
+        if not isinstance(result, dict):
             print _('An unexpected error has occurred.')
             print _('[Result]'), result
         else:

nova/auth/ldapdriver.py

@@ -85,7 +85,7 @@ def _clean(attr):
     """Clean attr for insertion into ldap"""
     if attr is None:
         return None
-    if type(attr) is unicode:
+    if isinstance(attr, unicode):
         return str(attr)
     return attr
 

nova/common/cfg.py

@@ -962,9 +962,9 @@ class ConfigOpts(object):
         :param value: the string value, or list of string values
         :returns: the substituted string(s)
         """
-        if type(value) is list:
+        if isinstance(value, list):
             return [self._substitute(i) for i in value]
-        elif type(value) is str:
+        elif isinstance(value, str):
             tmpl = string.Template(value)
             return tmpl.safe_substitute(self.StrSubWrapper(self))
         else:

nova/rpc/impl_carrot.py

@@ -24,11 +24,11 @@ No fan-out support yet.
 
 """
 
+import inspect
 import json
 import sys
 import time
 import traceback
-import types
 import uuid
 
 from carrot import connection as carrot_connection
@@ -284,7 +284,7 @@ class AdapterConsumer(Consumer):
         try:
             rval = node_func(context=ctxt, **node_args)
             # Check if the result was a generator
-            if isinstance(rval, types.GeneratorType):
+            if inspect.isgenerator(rval):
                 for x in rval:
                     ctxt.reply(x, None)
             else:

nova/rpc/impl_fake.py

@@ -17,9 +17,9 @@
 queues.  Casts will block, but this is very useful for tests.
 """
 
+import inspect
 import sys
 import traceback
-import types
 
 from nova import context
 from nova.rpc import common as rpc_common
@@ -60,7 +60,7 @@ class Consumer(object):
             # if ending not 'sent'...we might have more data to
             # return from the function itself
             if not ctxt._done:
-                if isinstance(rval, types.GeneratorType):
+                if inspect.isgenerator(rval):
                     for val in rval:
                         yield val
                 else:

nova/rpc/impl_kombu.py

@@ -18,11 +18,11 @@ import kombu
 import kombu.entity
 import kombu.messaging
 import kombu.connection
+import inspect
 import itertools
 import sys
 import time
 import traceback
-import types
 import uuid
 
 import eventlet
@@ -651,7 +651,7 @@ class ProxyCallback(object):
         try:
             rval = node_func(context=ctxt, **node_args)
             # Check if the result was a generator
-            if isinstance(rval, types.GeneratorType):
+            if inspect.isgenerator(rval):
                 for x in rval:
                     ctxt.reply(x, None)
             else:

nova/scheduler/distributed_scheduler.py

@@ -21,7 +21,6 @@ Weighing Functions.
 
 import json
 import operator
-import types
 
 import M2Crypto
 
@@ -358,7 +357,7 @@ class DistributedScheduler(driver.Scheduler):
             return getattr(filters, nm)
 
         return [get_itm(itm) for itm in dir(filters)
-                if (type(get_itm(itm)) is types.TypeType)
+                if isinstance(get_itm(itm), type)
                 and issubclass(get_itm(itm), filters.AbstractHostFilter)
                 and get_itm(itm) is not filters.AbstractHostFilter]
 

nova/scheduler/zone_manager.py

@@ -140,7 +140,7 @@ class ReadOnlyDict(UserDict.IterableUserDict):
             return
         elif isinstance(source, UserDict.UserDict):
             self.data = source.data
-        elif isinstance(source, type({})):
+        elif isinstance(source, dict):
             self.data = source
         else:
             raise TypeError

nova/utils.py

@@ -33,7 +33,6 @@ import socket
 import struct
 import sys
 import time
-import types
 import uuid
 import pyclbr
 from xml.sax import saxutils
@@ -176,11 +175,11 @@ def execute(*cmd, **kwargs):
     process_input = kwargs.pop('process_input', None)
     check_exit_code = kwargs.pop('check_exit_code', [0])
     ignore_exit_code = False
-    if type(check_exit_code) == int:
+    if isinstance(check_exit_code, bool):
-        check_exit_code = [check_exit_code]
-    elif type(check_exit_code) == bool:
         ignore_exit_code = not check_exit_code
         check_exit_code = [0]
+    elif isinstance(check_exit_code, int):
+        check_exit_code = [check_exit_code]
     delay_on_retry = kwargs.pop('delay_on_retry', True)
     attempts = kwargs.pop('attempts', 1)
     run_as_root = kwargs.pop('run_as_root', False)
@@ -569,7 +568,7 @@ class LazyPluggable(object):
                 raise exception.Error(_('Invalid backend: %s') % backend_name)
 
             backend = self.__backends[backend_name]
-            if type(backend) == type(tuple()):
+            if isinstance(backend, tuple):
                 name = backend[0]
                 fromlist = backend[1]
             else:
@@ -696,13 +695,13 @@ def to_primitive(value, convert_instances=False, level=0):
     # The try block may not be necessary after the class check above,
     # but just in case ...
     try:
-        if type(value) is type([]) or type(value) is type((None,)):
+        if isinstance(value, (list, tuple)):
             o = []
             for v in value:
                 o.append(to_primitive(v, convert_instances=convert_instances,
                                       level=level))
             return o
-        elif type(value) is type({}):
+        elif isinstance(value, dict):
             o = {}
             for k, v in value.iteritems():
                 o[k] = to_primitive(v, convert_instances=convert_instances,
@@ -858,7 +857,7 @@ def get_from_path(items, path):
     if items is None:
         return results
 
-    if not isinstance(items, types.ListType):
+    if not isinstance(items, list):
         # Wrap single objects in a list
         items = [items]
 
@@ -871,7 +870,7 @@ def get_from_path(items, path):
         child = get_method(first_token)
         if child is None:
             continue
-        if isinstance(child, types.ListType):
+        if isinstance(child, list):
             # Flatten intermediate lists
             for x in child:
                 results.append(x)