Fix division float over scalar and float over array

BARRIL-15

Add floor division support

Add changelog

Using CreateEmpty

Author: Arthur Besen Soprana

CHANGELOG.rst

@@ -4,6 +4,9 @@ UNRELEASED
 * ``_foundation`` has been renamed to ``_util``, and a lot of functions which were not being
   used anymore have been removed.
 * Add new unit category mass temperature per mol (``kg.K/mol``).
+* Fix division `1.0 / a` where `a` is a `Scalar` or `Array` and also add support for floor
+  division, i.e., operations like ``a // b``  where `a` and `b` are `Scalar` or `Array`
+  (and combinations with `float` or `int`).
 
 1.7.1 (2019-10-03)
 ------------------

src/barril/units/_array.py

@@ -4,8 +4,8 @@
 from oop_ext.interface._interface import ImplementsInterface
 
 from ._abstractvaluewithquantity import AbstractValueWithQuantityObject
-from .interfaces import IArray
 from ._quantity import Quantity
+from .interfaces import IArray
 
 __all__ = ["Array"]
 
@@ -246,6 +246,9 @@ def __iter__(self):
     def __truediv__(self, other):
         return self._DoOperation(self, other, "Divide")
 
+    def __floordiv__(self, other):
+        return self._DoOperation(self, other, "FloorDivide")
+
     def __mul__(self, other):
         return self._DoOperation(self, other, "Multiply")
 
@@ -256,6 +259,12 @@ def __sub__(self, other):
         return self._DoOperation(self, other, "Subtract")
 
     # Right-Basic operators ------------------------------------------------------------------------
+    def __rtruediv__(self, other):
+        return self._DoOperation(other, self, "Divide")
+
+    def __rfloordiv__(self, other):
+        return self._DoOperation(other, self, "FloorDivide")
+
     def __rdiv__(self, other):
         return self._DoOperation(other, self, "Divide")
 

src/barril/units/_scalar.py

@@ -8,8 +8,8 @@
 from oop_ext.interface._interface import ImplementsInterface
 
 from ._abstractvaluewithquantity import AbstractValueWithQuantityObject
-from .interfaces import IQuantity, IScalar
 from ._quantity import ObtainQuantity, Quantity
+from .interfaces import IQuantity, IScalar
 from .unit_database import UnitDatabase
 
 __all__ = ["Scalar"]
@@ -269,7 +269,8 @@ def __lt__(self, other):
     def __rtruediv__(self, other):
         return self._DoOperation(other, self, "Divide", lambda a, b: a / b)
 
-    __rfloordiv__ = __rtruediv__
+    def __rfloordiv__(self, other):
+        return self._DoOperation(other, self, "FloorDivide", lambda a, b: a // b)
 
     def __rmul__(self, other):
         return self._DoOperation(other, self, "Multiply", lambda a, b: a * b)
@@ -284,7 +285,8 @@ def __radd__(self, other):
     def __truediv__(self, other):
         return self._DoOperation(self, other, "Divide", lambda a, b: a / b)
 
-    __floordiv__ = __truediv__
+    def __floordiv__(self, other):
+        return self._DoOperation(self, other, "FloorDivide", lambda a, b: a // b)
 
     def __mul__(self, other):
         return self._DoOperation(self, other, "Multiply", lambda a, b: a * b)
@@ -302,7 +304,8 @@ def __pow__(self, exponent):
         return result
 
     def _DoOperation(self, p1, p2, operation, callback_operation):
-        if IsNumber(p1):
+        p1_is_number = IsNumber(p1)
+        if p1_is_number and operation not in ["Divide", "FloorDivide"]:
             return self.__class__.CreateWithQuantity(
                 self._quantity, callback_operation(p1, self._value)
             )
@@ -313,8 +316,19 @@ def _DoOperation(self, p1, p2, operation, callback_operation):
             )
 
         unit_database = self._unit_database
-        operation = getattr(unit_database, operation)
-        q, v = operation(p1.GetQuantity(), p2.GetQuantity(), self._value, p2.value)
+        operation_func = getattr(unit_database, operation)
+        if p1_is_number:
+            assert operation in [
+                "Divide",
+                "FloorDivide",
+            ], "Only operation Divide and FloorDivide allowed here!"
+            q, v = operation_func(
+                Quantity.CreateEmpty(), p2.GetQuantity(), p1, p2.value
+            )
+        else:
+            q, v = operation_func(
+                p1.GetQuantity(), p2.GetQuantity(), self._value, p2.value
+            )
         return self.__class__.CreateWithQuantity(q, v)
 
     def __reduce__(self):

src/barril/units/_tests/test_array.py

@@ -1,9 +1,8 @@
 import pytest
-from pytest import approx
-
 from collections import OrderedDict
 from barril import units
 from barril.units import Array, InvalidUnitError, ObtainQuantity, Quantity
+from pytest import approx
 
 
 def testEmptyArray():
@@ -215,6 +214,24 @@ def testDivision(unit_database_len_time):
     assert calculated1 == s1 / s2
 
 
+def testFloorDivision():
+    a = Array([3.5, 4.2], "m")
+    b = Array([100.0, 100.0], "cm")
+    assert approx((a // b).GetValues()) == [3.0, 4.0]
+    assert approx((350 // b).GetValues("1/cm")) == [3.0, 3.0]
+    assert approx((a // 1.0).GetValues("m")) == [3.0, 4.0]
+
+
+def testNumberOverArray():
+    a = Array([2.0, 2.0], "m")
+    b = Array([3.0, 3.0], "m")
+    c = 1.0 / a
+
+    assert approx(c.GetValues("1/m")) == [0.5, 0.5]
+    assert approx((3.0 / a).GetValues("1/m")) == [1.5, 1.5]
+    assert b / a == b * 1 / a == b * (1 / a)
+
+
 def testNumberInteractions(unit_database_len_time):
     import numpy
 

src/barril/units/_tests/test_derived_quantities.py

@@ -81,6 +81,9 @@ def testConvertionWithDerivedUnits(unit_database_len_time):
     # check division with cancelling units (and different categories)
     assert (empty, 1) == unit_database.Divide(m, m_city, 1, 1)
 
+    # floor division
+    assert (m, 3.0) == unit_database.FloorDivide(cat_mix_m2, km_city, 3.5, 0.001)
+
     # sum
     assert (m, 1 + 0.01) == unit_database.Sum(m, cm, 1, 1)
     assert (m, 2) == unit_database.Sum(m, m_city, 1, 1)

src/barril/units/_tests/test_scalar.py

@@ -3,18 +3,17 @@
 """
 
 import pytest
-from pytest import approx
-
 from collections import OrderedDict
 from barril import units
 from barril.units import (
+    ChangeScalars,
     InvalidOperationError,
     InvalidUnitError,
     ObtainQuantity,
     Quantity,
     Scalar,
-    ChangeScalars,
 )
+from pytest import approx
 
 
 def testScalarInterface(unit_database_well_length):
@@ -319,6 +318,22 @@ def testDivision(unit_database_len_time):
     assert calculated1 == s1 / s2
 
 
+def testFloorDivision():
+    a = Scalar(3.5, "m")
+    b = Scalar(100.0, "cm")
+    assert (a // b).GetValueAndUnit() == (3.0, "")
+    assert (350 // b).GetValueAndUnit() == (3.0, "1/cm")
+    assert (a // 1.0).GetValueAndUnit() == (3.0, "m")
+
+
+def testNumberOverScalar():
+    a = Scalar(2.0, "m")
+    b = Scalar(3.0, "m")
+    assert (1.0 / a).GetValueAndUnit() == (0.5, "1/m")
+    assert (3.0 / a).GetValueAndUnit() == (1.5, "1/m")
+    assert b / a == b * 1 / a == b * (1.0 / a)
+
+
 def testPow(unit_database_len_time):
     s = Scalar(2, "s", "Time")
     spow = s ** 3

src/barril/units/unit_database.py

@@ -1238,6 +1238,16 @@ def Divide(self, quantity1, quantity2, value1, value2):
             quantity1, quantity2, value1, value2, lambda a, b: a - b, lambda a, b: a / b
         )
 
+    def FloorDivide(self, quantity1, quantity2, value1, value2):
+        return self._DoOperationResultingInNewQuantity(
+            quantity1,
+            quantity2,
+            value1,
+            value2,
+            lambda a, b: a - b,
+            lambda a, b: a // b,
+        )
+
     def Multiply(self, quantity1, quantity2, value1, value2):
         """
         Multiplication with different quantities.