Split quantity (No __array_function__)

.travis.yml

@@ -22,6 +22,10 @@ env:
   - UNCERTAINTIES="N" PYTHON="3.5" NUMPY_VERSION=1.14 PANDAS=0
   - UNCERTAINTIES="Y" PYTHON="3.5" NUMPY_VERSION=1.14 PANDAS=0
   - UNCERTAINTIES="N" PYTHON="3.6" NUMPY_VERSION=1.14 PANDAS=0
+  # Test with the newer numpy versions
+  - UNCERTAINTIES="N" PYTHON="3.6" NUMPY_VERSION=1.17 PANDAS=0
+  - UNCERTAINTIES="N" PYTHON="3.6" NUMPY_VERSION=1.16 PANDAS=0
+
 
 before_install:
   - sudo apt-get update
@@ -51,6 +55,10 @@ before_install:
 install:
   - conda create --yes -n $ENV_NAME python=$PYTHON pip
   - source activate $ENV_NAME
+  - if [[ "$NUMPY_VERSION" == 1.17 ]]; then
+        conda config --add channels conda-forge;
+        conda config --set channel_priority strict;
+    fi
   - if [ $UNCERTAINTIES == 'Y' ]; then pip install 'uncertainties==2.4.7.1'; fi
   - if [ $NUMPY_VERSION != '0' ]; then conda install --yes numpy==$NUMPY_VERSION; fi
   - if [[ $TRAVIS_PYTHON_VERSION == '3.5' && $NUMPY_VERSION == 1.11.2 && $UNCERTAINTIES == "Y" ]]; then pip install babel serialize pyyaml; fi

pint/compat/__init__.py

@@ -73,6 +73,9 @@ def u(x):
     HAS_NUMPY = True
     NUMPY_VER = np.__version__
     NUMERIC_TYPES = (Number, Decimal, ndarray, np.number)
+
+    if "dev" in NUMPY_VER:
+        NUMPY_VER = NUMPY_VER[:NUMPY_VER.index("dev")-1]
 
     def _to_magnitude(value, force_ndarray=False):
         if isinstance(value, (dict, bool)) or value is None:
@@ -128,7 +131,7 @@ def _to_magnitude(value, force_ndarray=False):
     import pandas as pd
     HAS_PANDAS = True
     # pin Pandas version for now
-    HAS_PROPER_PANDAS = pd.__version__.startswith("0.24.0.dev0+625.gbdb7a16")
+    HAS_PROPER_PANDAS = pd.__version__.startswith("0.25")
 except ImportError:
     HAS_PROPER_PANDAS = HAS_PANDAS = False
 

pint/measurement.py

@@ -12,10 +12,12 @@
 from .compat import ufloat
 from .formatting import _FORMATS, siunitx_format_unit
 
+from .quantity import BaseQuantity
+
 MISSING = object()
 
 
-class _Measurement(object):
+class BaseMeasurement(object):
     """Implements a class to describe a quantity with uncertainty.
 
     :param value: The most likely value of the measurement.
@@ -24,7 +26,8 @@ class _Measurement(object):
     :type error: Quantity or Number
     """
 
-    def __new__(cls, value, error, units=MISSING):
+    @classmethod
+    def _new(cls, value, error, units=MISSING):
         if units is MISSING:
             try:
                 value, units = value.magnitude, value.units
@@ -47,8 +50,7 @@ def __new__(cls, value, error, units=MISSING):
             raise ValueError('The magnitude of the error cannot be negative'.format(value, error))
         else:
             mag = ufloat(value,error)
-
-        inst = super(_Measurement, cls).__new__(cls, mag, units)
+        inst = super(BaseMeasurement, cls)._new(mag, units)
         return inst
 
     @property
@@ -136,10 +138,21 @@ def __init__(self, *args):
                 raise RuntimeError("Pint requires the 'uncertainties' package to create a Measurement object.")
 
     else:
-        class Measurement(_Measurement, registry.Quantity):
-            pass
-
+        class Measurement(BaseMeasurement, registry.Quantity):
+            def __new__(cls, value, error, units=MISSING):
+                if hasattr(value, "__iter__"):
+                    return MeasurementSequence._new(value, error, units)
+                else:
+                    return MeasurementScalar._new(value, error, units)
     Measurement._REGISTRY = registry
     Measurement.force_ndarray = force_ndarray
 
+    class MeasurementScalar(Measurement):
+        def __new__(cls, value, error, units=MISSING):
+            inst = Measurement.__new__(Measurement, value, error, units)
+            return inst
+
+    class MeasurementSequence(Measurement):
+        def __new__(cls, value, error, units=MISSING):
+            inst = Measurement.__new__(Measurement, value, error, units)
     return Measurement