[json_backend] pylint+pep8 on json_backend.py

EditorialModel/backend/json_backend.py

@@ -7,38 +7,39 @@ import json
 import datetime
 from Lodel.utils.mlstring import MlString
 
+
 def date_cast(date):
     if len(date):
         return datetime.datetime(date)
     else:
         return None
 
+
 def int_or_none(i):
     if len(i):
         return int(i)
     else:
         return None
 
+
 ## Manages a Json file based backend structure
 class EmBackendJson(object):
 
     cast_methods = {
-        'uid' : int,
-        'rank' : int,
-        'class_id' : int,
-        'fieldgroup_id' : int,
-        'rel_to_type_id' : int_or_none,
-        'rel_field_id' : int_or_none,
-        'optional' : bool,
+        'uid': int,
+        'rank': int,
+        'class_id': int,
+        'fieldgroup_id': int,
+        'rel_to_type_id': int_or_none,
+        'rel_field_id': int_or_none,
+        'optional': bool,
         'internal': bool,
-        'string' : MlString.load,
-        'help_text' : MlString.load,
-        'date_create' : date_cast,
-        'date_update' : date_cast,
+        'string': MlString.load,
+        'help_text': MlString.load,
+        'date_create': date_cast,
+        'date_update': date_cast,
     }
 
-        
-
     ## Constructor
     #
     # @param json_file str: path to the json_file used as data source