validationError was moved to new file to avoid circular imports in the future

api/core.py

@@ -2,7 +2,7 @@ from flask import Flask, jsonify, Response, request
 from flask_sqlalchemy import SQLAlchemy
 from api.extensions.esales import Esales
 from api.helpers import check_api_key
-from api.validators import ValidationError
+from api.exceptions import ValidationError
 
 db = SQLAlchemy()
 esales = Esales()

api/exceptions.py

@@ -0,0 +1,7 @@
+# coding=UTF-8
+
+class ValidationError(Exception):
+
+    def __init__(self, message):
+        Exception.__init__(self)
+        self.message = message

api/validators.py

@@ -1,11 +1,5 @@
 # coding=UTF-8
-
-
-class ValidationError(Exception):
-
-    def __init__(self, message):
-        Exception.__init__(self)
-        self.message = message
+from api.exceptions import ValidationError
 
 
 def validate_keys_exists(obj, *keys):