Adds __str__ to Suberror

Resolves #217

recurly/errors.py

@@ -217,6 +217,9 @@ def __init__(self, field, symbol, message):
             self.symbol = symbol
             self.message = message
 
+        def __str__(self):
+            return self.__unicode__()
+
         def __unicode__(self):
             return six.u('%s: %s %s') % (self.symbol, self.field, self.message)
 
@@ -254,9 +257,15 @@ def errors(self):
         return suberrors
 
     def __unicode__(self):
-        return six.u('; ').join(six.text_type(error)
-                                for error in six.itervalues(self.errors))
-
+        all_error_strings = []
+        all_error_keys = sorted(self.errors.keys())
+        for error_key in all_error_keys:
+            error = self.errors[error_key]
+            if isinstance(error, (tuple, list)):
+                all_error_strings += [six.text_type(e) for e in error]  # multiple errors on field
+            else:
+                all_error_strings.append(six.text_type(error))
+        return six.u('; ').join(all_error_strings)
 
 class ServerError(ResponseError):
     """An error resulting from a problem creating the server's response

tests/test_resources.py

@@ -936,7 +936,7 @@ def test_subscribe_multiple_errors(self):
             # than one error on a field
             sub_errs = err.errors['subscription.account.account_code']
             self.assertEqual(len(sub_errs), 2)
-            self.assertEqual(type(sub_errs[1]), recurly.errors.ValidationError.Suberror)
+            self.assertEqual(str(err), "blank: subscription.account.account_code can't be blank; invalid: subscription.account.account_code is invalid; empty: subscription.account.billing_info.address1 can't be empty; empty: subscription.account.billing_info.city can't be empty; empty: subscription.account.billing_info.country can't be empty; blank: subscription.account.billing_info.first_name can't be blank; blank: subscription.account.billing_info.last_name can't be blank; required: subscription.account.billing_info.number is required; empty: subscription.account.billing_info.zip can't be empty; invalid: subscription.plan_code is invalid; not_a_number: subscription.unit_amount_in_cents is not a number")
         except e:
             self.fail("Failed subscription did not raise a Validation error")