Issue #19232: Speed up decimal import. Additionally, since _decimal is

self-contained, this change facilitates maintenance and the Python version
can be easily imported for experimentation.

Lib/test/test_decimal.py

@@ -4173,9 +4173,7 @@ class CheckAttributes(unittest.TestCase):
         self.assertEqual(C.__version__, P.__version__)
         self.assertEqual(C.__libmpdec_version__, P.__libmpdec_version__)
 
-        x = dir(C)
-        y = [s for s in dir(P) if '__' in s or not s.startswith('_')]
-        self.assertEqual(set(x) - set(y), set())
+        self.assertEqual(dir(C), dir(P))
 
     def test_context_attributes(self):
 

Modules/_decimal/tests/deccheck.py

@@ -36,6 +36,7 @@ from test.support import import_fresh_module
 from randdec import randfloat, all_unary, all_binary, all_ternary
 from randdec import unary_optarg, binary_optarg, ternary_optarg
 from formathelper import rand_format, rand_locale
+from _pydecimal import _dec_from_triple
 
 C = import_fresh_module('decimal', fresh=['_decimal'])
 P = import_fresh_module('decimal', blocked=['_decimal'])
@@ -370,7 +371,7 @@ class SkipHandler:
         return abs(a - b)
 
     def standard_ulp(self, dec, prec):
-        return P._dec_from_triple(0, '1', dec._exp+len(dec._int)-prec)
+        return _dec_from_triple(0, '1', dec._exp+len(dec._int)-prec)
 
     def rounding_direction(self, x, mode):
         """Determine the effective direction of the rounding when
@@ -401,10 +402,10 @@ class SkipHandler:
         # Convert infinities to the largest representable number + 1.
         x = exact
         if exact.is_infinite():
-            x = P._dec_from_triple(exact._sign, '10', context.p.Emax)
+            x = _dec_from_triple(exact._sign, '10', context.p.Emax)
         y = rounded
         if rounded.is_infinite():
-            y = P._dec_from_triple(rounded._sign, '10', context.p.Emax)
+            y = _dec_from_triple(rounded._sign, '10', context.p.Emax)
 
         # err = (rounded - exact) / ulp(rounded)
         self.maxctx.prec = p * 2