From 177ca5a3eec9a18e2af9ae7648be8fed37ff7697 Mon Sep 17 00:00:00 2001
From: Salvo 'LtWorf' Tomaselli <tiposchi@tiscali.it>
Date: Mon, 24 Aug 2020 18:42:18 +0200
Subject: [PATCH] Values can be None

---
 relational/rtypes.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/relational/rtypes.py b/relational/rtypes.py
index d493fd2..29f9aae 100644
--- a/relational/rtypes.py
+++ b/relational/rtypes.py
@@ -23,7 +23,7 @@
 import datetime
 import keyword
 import re
-from typing import Union, Set, Any, Callable, Type
+from typing import Union, Set, Any, Callable, Type, Optional
 from dataclasses import dataclass
 
 
@@ -31,7 +31,7 @@ RELATION_NAME_REGEXP = re.compile(r'^[_a-z][_a-z0-9]*$', re.IGNORECASE)
 _date_regexp = re.compile(
         r'^([0-9]{1,4})(\\|-|/)([0-9]{1,2})(\\|-|/)([0-9]{1,2})$'
     )
-CastValue = Union[str, int, float, 'Rdate']
+CastValue = Optional[Union[str, int, float, 'Rdate']]
 
 
 def guess_type(value: str) -> Set[Union[Callable[[Any], Any], Type['Rdate']]]: