Merge pull request #187 from CitrineInformatics/maintain/unit-exponents-issue

Correct fractional power formatting issue for units

Author: kroenlein

gemd/units/impl.py

@@ -81,11 +81,11 @@ def _format_clean(unit, registry, **options):
 
         if p == 1:
             numerator.append(u)
-        elif p > 1:
+        elif p > 0:
             numerator.append(f"{u} ** {p}")
         elif p == -1:
             denominator.append(u)
-        elif p < -1:
+        elif p < 0:
             denominator.append(f"{u} ** {-p}")
 
     if len(numerator) == 0:

gemd/units/tests/test_parser.py

@@ -142,3 +142,12 @@ def test_punctuation():
     assert parse_units('N.m') == parse_units('N * m')
     with pytest.raises(UndefinedUnitError):
         parse_units('mol : mol')
+
+
+def test_exponents():
+    """SPT-874 fractional exponents were being treated as zero."""
+    megapascals = parse_units("MPa")
+    sqrt_megapascals = parse_units('MPa^0.5')
+    assert megapascals in sqrt_megapascals
+    assert sqrt_megapascals == parse_units(f"{megapascals} / {sqrt_megapascals}")
+    assert parse_units('MPa^1.5') == parse_units(f"{megapascals} * {sqrt_megapascals}")

setup.py

@@ -2,7 +2,7 @@
 
 
 setup(name='gemd',
-      version='1.13.4',
+      version='1.13.5',
       url='http://github.com/CitrineInformatics/gemd-python',
       description="Python binding for Citrine's GEMD data model",
       author='Citrine Informatics',