1 files changed, 8 insertions, 5 deletions
diff --git a/type/centcount.py b/type/centcount.py
index 2cb99e0..4529695 100644
--- a/type/centcount.py
+++ b/type/centcount.py
@@ -1,7 +1,10 @@
 #!/usr/bin/env python3
 
+"""An amount of money (USD) represented as an integral count of
+cents."""
+
 import re
-from typing import Optional, Tuple, TypeVar
+from typing import Optional, Tuple
 
 import math_utils
 
@@ -36,9 +39,9 @@ class CentCount(object):
         a = round(a, 2)
         s = f'{a:,.2f}'
         if self.currency is not None:
-            return '%s %s' % (s, self.currency)
+            return f'{s} {self.currency}'
         else:
-            return '$%s' % s
+            return f'${s}'
 
     def __pos__(self):
         return CentCount(centcount=self.centcount, currency=self.currency)
@@ -181,8 +184,8 @@ class CentCount(object):
     def __ge__(self, other):
         return self > other or self == other
 
-    def __hash__(self):
-        return self.__repr__
+    def __hash__(self) -> int:
+        return hash(self.__repr__)
 
     CENTCOUNT_RE = re.compile(r"^([+|-]?)(\d+)(\.\d+)$")
     CURRENCY_RE = re.compile(r"^[A-Z][A-Z][A-Z]$")