Change the following to replace Python 2 code with Python 3:

1) Replace the deprecated unit test method.
2) Wraps filter usage in a list call.
3) Converts the old metaclass syntax to new.
4) Use range instead of xrange method.
5) Change Unicode to str.
6) Several other transformations.
7) Fixed change password test cases.
8) Use simplejson instead of plain JSON.

web/pgadmin/tools/sqleditor/command.py

@@ -169,7 +169,7 @@ class SQLFilter(object):
         self.did = kwargs['did']
         self.obj_id = kwargs['obj_id']
         sql_filter = kwargs.get('sql_filter', None)
-        self._row_filter = sql_filter if type(sql_filter) is str else None
+        self._row_filter = sql_filter if isinstance(sql_filter, str) else None
         self._data_sorting = kwargs.get('data_sorting', None)
         self._set_sorting_from_filter_dialog = False
 
@@ -212,7 +212,7 @@ class SQLFilter(object):
         Args:
             row_filter: sql query
         """
-        if type(row_filter) is not str:
+        if not isinstance(row_filter, str):
             row_filter = None
 
         status, msg = self.validate_filter(row_filter)