From 01dc9391d1c5f03df092777f1e8a0a30a816b5dc Mon Sep 17 00:00:00 2001
From: Salvo 'LtWorf' Tomaselli <tiposchi@tiscali.it>
Date: Fri, 5 Jun 2015 18:28:44 +0200
Subject: [PATCH] Adds len() to relation

Returns the cardinality
---
 relational/relation.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/relational/relation.py b/relational/relation.py
index bb1f442..8931db2 100644
--- a/relational/relation.py
+++ b/relational/relation.py
@@ -382,6 +382,9 @@ class relation (object):
         # comparing content
         return self.content == other.content
 
+    def __len__(self):
+        return len(self.content)
+
     def __str__(self):
         '''Returns a string representation of the relation, can be printed with
         monospaced fonts'''