Merge branch 'master' of git://github.com/CD3/pint into CD3-master

docs/tutorial.rst

@@ -248,6 +248,15 @@ If you want to use abbreviated unit names, prefix the specification with `~`:
 
 The same is true for latex (`L`) and HTML (`H`) specs.
 
+Pint also supports the LaTeX siunitx package:
+
+.. doctest::
+
+   >>> accel = 1.3 * ureg['meter/second**2']
+   >>> # siunitx Latex print
+   >>> print('The siunitx representation is {:Lx}'.format(accel))
+   The siunitx representation is \SI[]{1.3}{\meter\per\second\squared}
+
 Finally, you can specify a default format specification:
 
    >>> 'The acceleration is {}'.format(accel)

pint/formatting.py

@@ -190,6 +190,43 @@ def format_unit(unit, spec):
     return result
 
 
+def siunitx_format_unit(units):
+  '''Returns LaTeX code for the unit that can be put into an siunitx command.'''
+  # NOTE: unit registry is required to identify unit prefixes.
+  registry = units._REGISTRY
+
+  def _tothe(power):
+    if power == 1:
+      return ''
+    elif power == 2:
+      return r'\squared'
+    elif power == 3:
+      return r'\cubed'
+    else:
+      return r'\tothe{%d}' % (power)
+
+  l = []
+  # loop through all units in the container
+  for unit, power in sorted(units._units.items()):
+    # remove unit prefix if it exists
+    # siunit supports \prefix commands
+    prefix = None
+    for p in registry._prefixes.values():
+      p = str(p)
+      if len(p) > 0 and unit.find(p) == 0:
+        prefix = p
+        unit = unit.replace( prefix, '', 1 )
+        
+    if power < 0:
+      l.append(r'\per')
+    if not prefix is None:
+      l.append(r'\{0}'.format(prefix))
+    l.append(r'\{0}'.format(unit))
+    l.append(r'{0}'.format(_tothe(abs(power))))
+
+  return ''.join(l)
+
+
 def remove_custom_flags(spec):
     for flag in _KNOWN_TYPES:
          if flag:

pint/measurement.py

@@ -10,7 +10,7 @@
 from __future__ import division, unicode_literals, print_function, absolute_import
 
 from .compat import ufloat
-from .formatting import _FORMATS
+from .formatting import _FORMATS, siunitx_format_unit
 
 MISSING = object()
 
@@ -65,6 +65,22 @@ class _Measurement(object):
         return '{0}'.format(self)
 
     def __format__(self, spec):
+        # special cases
+        if 'Lx' in spec: # the LaTeX siunitx code
+          # the uncertainties module supports formatting 
+          # numbers in value(unc) notation (i.e. 1.23(45) instead of 1.23 +/- 0.45),
+          # which siunitx actually accepts as input. we just need to give the 'S'
+          # formatting option for the uncertainties module.
+          spec = spec.replace('Lx','S')
+          # todo: add support for extracting options
+          opts = 'separate-uncertainty=true'
+          mstr = format( self.magnitude, spec )
+          ustr = siunitx_format_unit(self.units)
+          ret = r'\SI[%s]{%s}{%s}'%( opts, mstr, ustr )
+          return ret
+
+
+        # standard cases
         if 'L' in spec:
             newpm = pm = r'  \pm  '
             pars = _FORMATS['L']['parentheses_fmt']

pint/quantity.py

@@ -15,7 +15,7 @@ import operator
 import functools
 import bisect
 
-from .formatting import remove_custom_flags
+from .formatting import remove_custom_flags, siunitx_format_unit
 from .errors import (DimensionalityError, OffsetUnitCalculusError,
                      UndefinedUnitError)
 from .definitions import UnitDefinition
@@ -118,6 +118,18 @@ class _Quantity(SharedRegistryObject):
 
     def __format__(self, spec):
         spec = spec or self.default_format
+
+        # special cases
+        if 'Lx' in spec: # the LaTeX siunitx code
+          spec = spec.replace('Lx','')
+          # todo: add support for extracting options
+          opts = ''
+          mstr = format(self.magnitude,spec)
+          ustr = siunitx_format_unit(self.units)
+          ret = r'\SI[%s]{%s}{%s}'%( opts, mstr, ustr )
+          return ret
+
+        # standard cases
         if '#' in spec:
             spec = spec.replace('#', '')
             obj = self.to_compact()

pint/testsuite/test_measurement.py

@@ -51,11 +51,13 @@ class TestMeasurement(QuantityTestCase):
         self.assertEqual('{0:L}'.format(m), r'\left(4.00 \pm 0.10\right) second^{2}')
         self.assertEqual('{0:H}'.format(m), '(4.00 &plusmn; 0.10) second<sup>2</sup>')
         self.assertEqual('{0:C}'.format(m), '(4.00+/-0.10) second**2')
+        self.assertEqual('{0:Lx}'.format(m), r'\SI[separate-uncertainty=true]{4.00(10)}{\second\squared}')
         self.assertEqual('{0:.1f}'.format(m), '(4.0 +/- 0.1) second ** 2')
         self.assertEqual('{0:.1fP}'.format(m), '(4.0 ± 0.1) second²')
         self.assertEqual('{0:.1fL}'.format(m), r'\left(4.0 \pm 0.1\right) second^{2}')
         self.assertEqual('{0:.1fH}'.format(m), '(4.0 &plusmn; 0.1) second<sup>2</sup>')
         self.assertEqual('{0:.1fC}'.format(m), '(4.0+/-0.1) second**2')
+        self.assertEqual('{0:.1fLx}'.format(m), '\SI[separate-uncertainty=true]{4.0(1)}{\second\squared}')
 
     def test_format_paru(self):
         v, u = self.Q_(0.20, 's ** 2'), self.Q_(0.01, 's ** 2')
@@ -75,6 +77,8 @@ class TestMeasurement(QuantityTestCase):
         self.assertEqual('{0:.3uL}'.format(m), r'\left(0.2000 \pm 0.0100\right) second^{2}')
         self.assertEqual('{0:.3uH}'.format(m), '(0.2000 &plusmn; 0.0100) second<sup>2</sup>')
         self.assertEqual('{0:.3uC}'.format(m), '(0.2000+/-0.0100) second**2')
+        self.assertEqual('{0:.3uLx}'.format(m), '\SI[separate-uncertainty=true]{0.2000(100)}{\second\squared}')
+        self.assertEqual('{0:.1uLx}'.format(m), '\SI[separate-uncertainty=true]{0.20(1)}{\second\squared}')
 
     def test_format_percu(self):
         self.test_format_perce()

pint/testsuite/test_quantity.py

@@ -104,6 +104,7 @@ class TestQuantity(QuantityTestCase):
                              ('{0:P~}', '4.12345678 kg·m²/s'),
                              ('{0:H~}', '4.12345678 kg m<sup>2</sup>/s'),
                              ('{0:C~}', '4.12345678 kg*m**2/s'),
+                             ('{0:Lx}', r'\SI[]{4.12345678}{\kilo\gram\meter\squared\per\second}'),
                              ):
             self.assertEqual(spec.format(x), result)
 

pint/testsuite/test_unit.py

@@ -32,6 +32,7 @@ class TestUnit(QuantityTestCase):
                              ('{0:P}', 'kilogram·meter²/second'),
                              ('{0:H}', 'kilogram meter<sup>2</sup>/second'),
                              ('{0:C}', 'kilogram*meter**2/second'),
+                             ('{0:Lx}', r'\si[]{\kilo\gram\meter\squared\per\second}'),
                              ('{0:~}', 'kg * m ** 2 / s'),
                              ('{0:L~}', r'\frac{kg \cdot m^{2}}{s}'),
                              ('{0:P~}', 'kg·m²/s'),

pint/unit.py

@@ -30,6 +30,7 @@ from .util import (logger, pi_theorem, solve_dependencies, ParserHelper,
                    find_shortest_path, UnitsContainer, _is_dim,
                    SharedRegistryObject, to_units_container)
 from .compat import tokenizer, string_types, NUMERIC_TYPES, long_type, zip_longest
+from .formatting import siunitx_format_unit
 from .definitions import (Definition, UnitDefinition, PrefixDefinition,
                           DimensionDefinition)
 from .converters import ScaleConverter
@@ -99,6 +100,13 @@ class _Unit(SharedRegistryObject):
 
     def __format__(self, spec):
         spec = spec or self.default_format
+        # special cases
+        if 'Lx' in spec: # the LaTeX siunitx code
+          opts = ''
+          ustr = siunitx_format_unit(self)
+          ret = r'\si[%s]{%s}'%( opts, ustr )
+          return ret
+
 
         if '~' in spec:
             if self.dimensionless:

pint/util.py

@@ -22,7 +22,7 @@ from token import STRING, NAME, OP, NUMBER
 from tokenize import untokenize
 
 from .compat import string_types, tokenizer, lru_cache, NullHandler, maketrans, NUMERIC_TYPES
-from .formatting import format_unit
+from .formatting import format_unit,siunitx_format_unit
 from .pint_eval import build_eval_tree
 
 logger = logging.getLogger(__name__)