Add unit conversions for inches.

doc/conf.py

@@ -25,7 +25,14 @@
 
 # Add any Sphinx extension module names here, as strings. They can be extensions
 # coming with Sphinx (named 'sphinx.ext.*') or your custom ones.
-extensions = ['sphinx.ext.autodoc', 'sphinx.ext.doctest', 'sphinx.ext.todo', 'sphinx.ext.coverage', 'sphinx.ext.viewcode']
+extensions = '''
+    sphinx.ext.autodoc
+    sphinx.ext.coverage
+    sphinx.ext.doctest
+    sphinx.ext.napoleon
+    sphinx.ext.todo
+    sphinx.ext.viewcode
+'''.split()
 
 # Add any paths that contain templates here, relative to this directory.
 templates_path = ['.templates']
@@ -41,7 +48,7 @@
 
 # General information about the project.
 project = u'quantiphy'
-copyright = u'2017, Ken Kundert'
+copyright = u'2017-2018, Ken Kundert'
 
 # The version info for the project you're documenting, acts as replacement for
 # |version| and |release|, also used in various other places throughout the

doc/user.rst

@@ -371,14 +371,15 @@ To do this conversion, *QuantiPhy* examines the given units (°F) and the desire
 units (K) and chooses the appropriate converter.  *QuantiPhy* provides 
 a collection of pre-defined converters for common units:
 
-====== ===============================================================
+====== ================================================================
 K:     K, F, °F, R, °R
 C, °C: K, C, °C, F, °F, R, °R
-m:     km, m, cm, mm, um, μm, micron, nm, Å, angstrom, mi, mile, miles
+m:     km, m, cm, mm, um, μm, micron, nm, Å, angstrom, mi, mile, miles,
+       in, inch, inches
 g:     oz, lb, lbs
-s:     s, sec, min, hour, hr , day
+s:     s, sec, min, hour, hr, day
 b:     B
-====== ===============================================================
+====== ================================================================
 
 You can also create your own converters using :class:`quantiphy.UnitConversion`:
 

quantiphy.py

@@ -298,6 +298,7 @@ def __str__(self):
 UnitConversion('m', 'nm', 1/1000000000)
 UnitConversion('m', 'Å angstrom', 1/10000000000)
 UnitConversion('m', 'mi mile miles', 1609.344)
+UnitConversion('m', 'in inch inches', 0.0254)
 
 # Mass conversions {{{2
 UnitConversion('g', 'lb lbs', 453.59237)

test_unit_conversion.py

@@ -124,6 +124,9 @@ def test_distance():
     assert q.render(scale='mi') == '621.37 umi'
     assert q.render(scale='mile') == '621.37 umile'
     assert q.render(scale='miles') == '621.37 umiles'
+    assert q.render(scale='in') == '39.37 in'
+    assert q.render(scale='inch') == '39.37 inch'
+    assert q.render(scale='inches') == '39.37 inches'
 
     q=Quantity('1_m')
     assert q.render() == '1 m'