From: Raymond Hettinger <python@rcn.com>
Date: Tue, 3 Feb 2009 03:54:28 +0000 (+0000)
Subject: Register decimals as numbers.Number
X-Git-Tag: v3.1a1~299
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=82417ca9b257133e37e5339b29f67160ad568722;p=python

Register decimals as numbers.Number
---

diff --git a/Lib/decimal.py b/Lib/decimal.py
index 4f9be21ccb..c46037e474 100644
--- a/Lib/decimal.py
+++ b/Lib/decimal.py
@@ -136,6 +136,7 @@ __all__ = [
 
 import copy as _copy
 import math as _math
+import numbers as _numbers
 
 try:
     from collections import namedtuple as _namedtuple
@@ -3695,6 +3696,12 @@ def _dec_from_triple(sign, coefficient, exponent, special=False):
 
     return self
 
+# Register Decimal as a kind of Number (an abstract base class).
+# However, do not register it as Real (because Decimals are not
+# interoperable with floats).
+_numbers.Number.register(Decimal)
+
+
 ##### Context class #######################################################
 
 
diff --git a/Lib/test/test_decimal.py b/Lib/test/test_decimal.py
index 798f4d8094..f40de8f207 100644
--- a/Lib/test/test_decimal.py
+++ b/Lib/test/test_decimal.py
@@ -30,6 +30,7 @@ import os, sys
 import pickle, copy
 import unittest
 from decimal import *
+import numbers
 from test.support import (TestSkipped, run_unittest, run_doctest,
                                is_resource_enabled)
 import random
@@ -1388,6 +1389,12 @@ class DecimalUsabilityTest(unittest.TestCase):
 
 class DecimalPythonAPItests(unittest.TestCase):
 
+    def test_abc(self):
+        self.assert_(issubclass(Decimal, numbers.Number))
+        self.assert_(not issubclass(Decimal, numbers.Real))
+        self.assert_(isinstance(Decimal(0), numbers.Number))
+        self.assert_(not isinstance(Decimal(0), numbers.Real))
+
     def test_pickle(self):
         d = Decimal('-3.141590000')
         p = pickle.dumps(d)