Issue #5920: Changed format.__float__ and complex.__float__ to use a precision of 12 when using the empty presentation type. This more closely matches str()'s behavior and reduces surprises when adding alignment flags to an empty format string. Patch by Mark Dickinson.
diff --git a/Lib/test/test_float.py b/Lib/test/test_float.py
index fb6daaf..b617fa3 100644
--- a/Lib/test/test_float.py
+++ b/Lib/test/test_float.py
@@ -284,6 +284,13 @@
self.assertEqual(format(0.01, ''), '0.01')
self.assertEqual(format(0.01, 'g'), '0.01')
+ # empty presentation type should format in the same way as str
+ # (issue 5920)
+ x = 100/7.
+ self.assertEqual(format(x, ''), str(x))
+ self.assertEqual(format(x, '-'), str(x))
+ self.assertEqual(format(x, '>'), str(x))
+ self.assertEqual(format(x, '2'), str(x))
self.assertEqual(format(1.0, 'f'), '1.000000')