Add fast route for operations with non-SI units

RELEASE_NOTES.md

@@ -1,3 +1,7 @@
+# Next Release
+
+- [#907](https://github.com/IAMconsortium/pyam/pull/907) Add fast route for operations with non-SI units
+
 # Release v3.1.0
 
 ## Highlights

pyam/_ops.py

@@ -83,7 +83,7 @@ def _op_data(df, name, method, axis, fillna=None, args=(), ignore_units=False, *
         and fillna is None
         and len(_unit_kwds["a"]) == 1
         and len(_unit_kwds["b"]) == 1
-        and registry.Unit(_unit_kwds["a"][0]) == registry.Unit(_unit_kwds["b"][0])
+        and _unit_kwds["a"][0] == _unit_kwds["b"][0]
     ):
         # activate ignore-units feature
         ignore_units = _unit_kwds["a"][0] if method in [add, subtract] else ""

tests/test_ops.py

@@ -96,6 +96,21 @@ def test_add_variable(test_df_year, arg, df_func, fillna, ignore_units, append):
         assert_iamframe_equal(exp, obs)
 
 
+@pytest.mark.parametrize("append", (False, True))
+def test_add_scenario_non_si_unit(test_df_year, append):
+    df = test_df_year.rename(unit={"EJ/yr": "foo"})
+    exp = df_ops_variable(operator.add, "Sum", unit="foo", meta=test_df_year.meta)
+    args = ("Primary Energy", "Primary Energy|Coal", "Sum")
+
+    if append:
+        obs = df.copy()
+        obs.add(*args, append=True)
+        assert_iamframe_equal(df.append(exp), obs)
+    else:
+        obs = df.add(*args)
+        assert_iamframe_equal(exp, obs)
+
+
 @pytest.mark.parametrize("append", (False, True))
 def test_add_scenario(test_df_year, append):
     """Verify that in-dataframe addition works on a custom axis (`scenario`)"""
@@ -159,6 +174,22 @@ def test_subtract_variable(test_df_year, arg, df_func, fillna, append, ignore_un
         assert_iamframe_equal(exp, test_df_year.subtract(*args, **kwds))
 
 
+@pytest.mark.parametrize("append", (False, True))
+def test_subtract_scenario_non_si_unit_unit(test_df_year, append):
+    df = test_df_year.rename(unit={"EJ/yr": "foo"})
+    exp = df_ops_variable(operator.sub, "Diff", unit="foo", meta=test_df_year.meta)
+    args = ("Primary Energy", "Primary Energy|Coal", "Diff")
+
+    if append:
+        obs = df.copy()
+        obs.subtract(*args, append=True)
+        assert_iamframe_equal(df.append(exp), obs)
+    else:
+        obs = df.subtract(*args)
+        assert_iamframe_equal(exp, obs)
+
+
+
 @pytest.mark.parametrize("append", (False, True))
 def test_subtract_scenario(test_df_year, append):
     """Verify that in-dataframe subtraction works on a custom axis (`scenario`)"""
@@ -288,6 +319,21 @@ def test_divide_variable(test_df_year, arg, df_func, fillna, append, ignore_unit
         assert_iamframe_equal(exp, test_df_year.divide(*args, **kwds))
 
 
+@pytest.mark.parametrize("append", (False, True))
+def test_divide_variable_non_si_unit_unit(test_df_year, append):
+    df = test_df_year.rename(unit={"EJ/yr": "foo"})
+    exp = df_ops_variable(operator.truediv, "Ratio", unit="", meta=test_df_year.meta)
+    args = ("Primary Energy", "Primary Energy|Coal", "Ratio")
+
+    if append:
+        obs = df.copy()
+        obs.divide(*args, append=True)
+        assert_iamframe_equal(df.append(exp), obs)
+    else:
+        obs = df.divide(*args)
+        assert_iamframe_equal(exp, obs)
+
+
 @pytest.mark.parametrize("append", (False, True))
 def test_divide_scenario(test_df_year, append):
     """Verify that in-dataframe addition works on a custom axis (`scenario`)"""