exception objects stringification

1 files changed, 7 insertions, 2 deletions

diff --git a/talerbank/app/amount.py b/talerbank/app/amount.py
index 6c17610..0453c35 100644
--- a/talerbank/app/amount.py
+++ b/talerbank/app/amount.py
@@ -23,11 +23,16 @@
 #  which might need it.
 
 class CurrencyMismatch(Exception):
-    pass
+    def __init__(self, msg):
+        self.msg = msg
+    def __str__(self):
+        return self.msg
 
 class BadFormatAmount(Exception):
     def __init__(self, faulty_str):
         self.faulty_str = faulty_str
+    def __str__(self):
+        return self.faulty_str
 
 class Amount:
     # How many "fraction" units make one "value" unit of currency
@@ -77,7 +82,7 @@ class Amount:
     @staticmethod
     def cmp(am1, am2):
         if am1.currency != am2.currency:
-            raise CurrencyMismatch()
+            raise CurrencyMismatch("%s vs %s" % (am1.currency, am2.currency))
         if am1.value == am2.value:
             if am1.fraction < am2.fraction:
                 return -1