added the format_babel method to show the units as translated in babel

pint/formatting.py

@@ -13,6 +13,8 @@ from __future__ import division, unicode_literals, print_function, absolute_impo
 
 import re
 
+from .babel_units import babel_units, babel_forms
+
 __JOIN_REG_EXP = re.compile("\{\d*\}")
 
 
@@ -100,7 +102,8 @@ _FORMATS = {
 
 def formatter(items, as_ratio=True, single_denominator=False,
               product_fmt=' * ', division_fmt=' / ', power_fmt='{0} ** {1}',
-              parentheses_fmt='({0})', exp_call=lambda x: '{0:n}'.format(x)):
+              parentheses_fmt='({0})', exp_call=lambda x: '{0:n}'.format(x),
+              locale=None, form='long', plural_form='one'):
     """Format a list of (name, exponent) pairs.
 
     :param items: a list of (name, exponent) pairs.
@@ -126,6 +129,24 @@ def formatter(items, as_ratio=True, single_denominator=False,
     pos_terms, neg_terms = [], []
 
     for key, value in sorted(items):
+        if locale and form and plural_form:
+            _key = babel_units.get(key)
+            if _key:
+                patterns = locale.unit_patterns
+                for _form in [form] + babel_forms:
+                    pattern_key = _key + ':' + _form
+                    if pattern_key in patterns:
+                        plural = plural_form
+                        if value <= 0:
+                            plural = 'one'
+                        pattern = patterns[pattern_key][plural]
+                        key = pattern.replace('{0}', '').strip()
+                        break
+                per_form = 'compound:per:' + form
+                if per_form in patterns:
+                    division_fmt = patterns[per_form]
+                power_fmt = '{0}{1}'
+                exp_call = _pretty_fmt_exponent
         if value == 1:
             pos_terms.append(key)
         elif value > 0:
@@ -177,12 +198,13 @@ def _parse_spec(spec):
     return result
 
 
-def format_unit(unit, spec):
+def format_unit(unit, spec, **kwspec):
     if not unit:
         return 'dimensionless'
 
     spec = _parse_spec(spec)
-    fmt = _FORMATS[spec]
+    fmt = dict(_FORMATS[spec])
+    fmt.update(kwspec)
 
     result = formatter(unit.items(), **fmt)
     if spec == 'L':

pint/quantity.py

@@ -141,6 +141,21 @@ class _Quantity(SharedRegistryObject):
             format(obj.magnitude, remove_custom_flags(spec)),
             format(obj.units, spec)).replace('\n', '')
 
+    def format_babel(self, spec='', **kwspec):
+        spec = spec or self.default_format
+
+        # standard cases
+        if '#' in spec:
+            spec = spec.replace('#', '')
+            obj = self.to_compact()
+        else:
+            obj = self
+        kwspec = dict(kwspec)
+        kwspec['plural_form'] = kwspec['locale'].plural_form(obj.magnitude)
+        return '{0} {1}'.format(
+            format(obj.magnitude, remove_custom_flags(spec)),
+            obj.units.format_babel(spec, **kwspec)).replace('\n', '')
+
     # IPython related code
     def _repr_html_(self):
         return self.__format__('H')

pint/unit.py

@@ -111,6 +111,21 @@ class _Unit(SharedRegistryObject):
 
         return '%s' % (format(units, spec))
 
+    def format_babel(self, spec='', **kwspec):
+        spec = spec or self.default_format
+
+        if '~' in spec:
+            if self.dimensionless:
+                return ''
+            units = UnitsContainer(dict((self._REGISTRY._get_symbol(key),
+                                         value)
+                                   for key, value in self._units.items()))
+            spec = spec.replace('~', '')
+        else:
+            units = self._units
+
+        return '%s' % (units.format_babel(spec, **kwspec))
+
     # IPython related code
     def _repr_html_(self):
         return self.__format__('H')

pint/util.py

@@ -325,6 +325,9 @@ class UnitsContainer(Mapping):
     def __format__(self, spec):
         return format_unit(self, spec)
 
+    def format_babel(self, spec, **kwspec):
+        return format_unit(self, spec, **kwspec)
+
     def __copy__(self):
         return UnitsContainer(self._d)