Support the option to format a number with no rounding. Useful for De…

…cimals
zopefoundation · Jan 5, 2017 · a21ad14 · a21ad14
1 parent 5add871
commit a21ad14
Show file tree

Hide file tree

Showing 3 changed files with 19 additions and 6 deletions.
diff --git a/CHANGES.rst b/CHANGES.rst
@@ -13,6 +13,10 @@ CHANGES
   special treatment, because standard str(x) collapses them to scientific
   representation.
 
+- Support for specifying rounding in NumberFormatter. This is required in some
+  cases, e.g. when you format a Decimal('0.9999') that sould not be rounded.
+  Currently, formatting Decimal('0.99999') will raise a TypeError if rounding
+  is not set to False
 
 4.1.0 (2015-11-06)
 ------------------

diff --git a/src/zope/i18n/format.py b/src/zope/i18n/format.py
@@ -327,8 +327,11 @@ def _format_integer(self, integer, pattern):
             integer = self.symbols['nativeZeroDigit']*(min_size-size) + integer
         return integer
 
-    def _format_fraction(self, fraction, pattern):
-        max_precision = len(pattern)
+    def _format_fraction(self, fraction, pattern, rounding=True):
+        if rounding:
+            max_precision = len(pattern)
+        else:
+            max_precision = sys.maxint
         min_precision = pattern.count('0')
         precision = len(fraction)
         roundInt = False
@@ -356,7 +359,7 @@ def _format_fraction(self, fraction, pattern):
             fraction = self.symbols['decimal'] + fraction
         return fraction, roundInt
 
-    def format(self, obj, pattern=None):
+    def format(self, obj, pattern=None, rounding=True):
         "See zope.i18n.interfaces.IFormat"
         # Make or get binary form of datetime pattern
         if pattern is not None:
@@ -410,7 +413,8 @@ def format(self, obj, pattern=None):
                 number = ''.join(obj_int_frac)
 
             fraction, roundInt = self._format_fraction(number[1:],
-                                                       bin_pattern[FRACTION])
+                                                       bin_pattern[FRACTION],
+                                                       rounding=rounding)
             if roundInt:
                 number = str(int(number[0]) + 1) + fraction
             else:
@@ -426,8 +430,8 @@ def format(self, obj, pattern=None):
 
         else:
             if len(obj_int_frac) > 1:
-                fraction, roundInt = self._format_fraction(obj_int_frac[1],
-                                                 bin_pattern[FRACTION])
+                fraction, roundInt = self._format_fraction(
+                    obj_int_frac[1], bin_pattern[FRACTION], rounding=rounding)
             else:
                 fraction = ''
                 roundInt = False

diff --git a/src/zope/i18n/tests/test_formats.py b/src/zope/i18n/tests/test_formats.py
@@ -1181,6 +1181,11 @@ def testFormatSmallNumbers(self):
             -1e-7, '(#0.00#####);(-#0.00#####)'), '(-0.0000001)')
         self.assertEqual(self.format.format(1e-9, '(#0.00###)'), '(0.00)')
 
+    def testNoRounding(self):
+        # Witout Rounding
+        self.assertEqual(self.format.format(
+            decimal.Decimal('0.99999'), '0.###', rounding=False), '0.99999')
+
 
 def test_suite():
     return TestSuite((