factor out common IPython code

3 files changed, 28 insertions, 36 deletions

diff --git a/pint/quantity.py b/pint/quantity.py
index 85656ed..e3f384f 100644
--- a/pint/quantity.py
+++ b/pint/quantity.py
@@ -25,7 +25,7 @@ from .errors import (DimensionalityError, OffsetUnitCalculusError,
                      UndefinedUnitError)
 from .definitions import UnitDefinition
 from .compat import string_types, ndarray, np, _to_magnitude, long_type
-from .util import (logger, UnitsContainer, SharedRegistryObject,
+from .util import (PrettyIPython, logger, UnitsContainer, SharedRegistryObject,
                    to_units_container, infer_base_unit,
                    fix_str_conversions)
 from pint.compat import Loc
@@ -66,7 +66,7 @@ def ireduce_dimensions(f):
 
 
 @fix_str_conversions
-class _Quantity(SharedRegistryObject):
+class _Quantity(PrettyIPython, SharedRegistryObject):
     """Implements a class to describe a physical quantity:
     the product of a numerical value and a unit of measurement.
 
@@ -225,25 +225,6 @@ class _Quantity(SharedRegistryObject):
             format(obj.magnitude, remove_custom_flags(spec)),
             obj.units.format_babel(spec, **kwspec)).replace('\n', '')
 
-    # IPython related code
-    def _repr_html_(self):
-        if "~" in self.default_format:
-            return "{:~H}".format(self)
-        else:
-            return "{:H}".format(self)
-
-    def _repr_latex_(self):
-        if "~" in self.default_format:
-            return "${:~L}$".format(self)
-        else:
-            return "${:L}$".format(self)
-
-    def _repr_pretty_(self, p, cycle):
-        if "~" in self.default_format:
-            p.text("{:~P}".format(self))
-        else:
-            p.text("{:P}".format(self))
-
     @property
     def magnitude(self):
         """Quantity's magnitude. Long form for `m`
diff --git a/pint/unit.py b/pint/unit.py
index c8a3495..4f8c35e 100644
--- a/pint/unit.py
+++ b/pint/unit.py
@@ -15,7 +15,8 @@ import copy
 import operator
 from numbers import Number
 
-from .util import UnitsContainer, SharedRegistryObject, fix_str_conversions
+from .util import (
+    PrettyIPython, UnitsContainer, SharedRegistryObject, fix_str_conversions)
 
 from .compat import string_types, NUMERIC_TYPES, long_type
 from .formatting import siunitx_format_unit
@@ -23,7 +24,7 @@ from .definitions import UnitDefinition
 
 
 @fix_str_conversions
-class _Unit(SharedRegistryObject):
+class _Unit(PrettyIPython, SharedRegistryObject):
     """Implements a class to describe a unit supporting math operations.
 
     :type units: UnitsContainer, str, Unit or Quantity.
@@ -110,19 +111,6 @@ class _Unit(SharedRegistryObject):
 
         return '%s' % (units.format_babel(spec, **kwspec))
 
-    # IPython related code
-    def _repr_html_(self):
-        if "~" in self.default_format:
-            return "{:~H}".format(self)
-        else:
-            return "{:H}".format(self)
-
-    def _repr_latex_(self):
-        if "~" in self.default_format:
-            return "${:~L}$".format(self)
-        else:
-            return "${:L}$".format(self)
-
     @property
     def dimensionless(self):
         """Return true if the Unit is dimensionless.
diff --git a/pint/util.py b/pint/util.py
index df9a12f..a4b089c 100644
--- a/pint/util.py
+++ b/pint/util.py
@@ -625,6 +625,29 @@ class SharedRegistryObject(object):
         else:
             return False
 
+
+class PrettyIPython(object):
+    """Mixin to add pretty-printers for IPython"""
+
+    def _repr_html_(self):
+        if "~" in self.default_format:
+            return "{:~H}".format(self)
+        else:
+            return "{:H}".format(self)
+
+    def _repr_latex_(self):
+        if "~" in self.default_format:
+            return "${:~L}$".format(self)
+        else:
+            return "${:L}$".format(self)
+
+    def _repr_pretty_(self, p, cycle):
+        if "~" in self.default_format:
+            p.text("{:~P}".format(self))
+        else:
+            p.text("{:P}".format(self))
+
+
 def to_units_container(unit_like, registry=None):
     """ Convert a unit compatible type to a UnitsContainer.