From 34aead2485a48f63b1731f92c892c859e68c5225 Mon Sep 17 00:00:00 2001
From: Paul Molodowitch <pm@stanfordalumni.org>
Date: Mon, 23 Dec 2013 14:35:00 -0800
Subject: [PATCH] error if unknown extension given

---
 dominion_tabs.py | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/dominion_tabs.py b/dominion_tabs.py
index f68af6c..df0835e 100644
--- a/dominion_tabs.py
+++ b/dominion_tabs.py
@@ -706,7 +706,18 @@ class DominionTabs:
 
         if self.options.expansions:
             self.options.expansions = [o.lower() for o in self.options.expansions]
-            cards=[c for c in cards if c.cardset in self.options.expansions]
+            filteredCards = []
+            knownExpansions = set()
+            for c in cards:
+                knownExpansions.add(c.cardset)
+                if c.cardset in self.options.expansions:
+                    filteredCards.append(c)
+            unknownExpansions = set(self.options.expansions) - knownExpansions
+            if unknownExpansions:
+                print "Error - unknown expansion(s): %s" % ", ".join(unknownExpansions)
+                return
+
+            cards = filteredCards
 
         if options.expansion_dividers:
             cardnamesByExpansion = {}