cut/paste AccessorProperty and PandasDelegate to core.accessor (#17651)

Author: jbrockmendel

pandas/core/accessor.py

@@ -5,6 +5,7 @@
 that can be mixed into or pinned onto other pandas classes.
 
 """
+from pandas.core.common import AbstractMethodError
 
 
 class DirNamesMixin(object):
@@ -33,3 +34,97 @@ def __dir__(self):
         rv = set(dir(type(self)))
         rv = (rv - self._dir_deletions()) | self._dir_additions()
         return sorted(rv)
+
+
+class AccessorProperty(object):
+    """Descriptor for implementing accessor properties like Series.str
+    """
+
+    def __init__(self, accessor_cls, construct_accessor=None):
+        self.accessor_cls = accessor_cls
+        self.construct_accessor = (construct_accessor or
+                                   accessor_cls._make_accessor)
+        self.__doc__ = accessor_cls.__doc__
+
+    def __get__(self, instance, owner=None):
+        if instance is None:
+            # this ensures that Series.str.<method> is well defined
+            return self.accessor_cls
+        return self.construct_accessor(instance)
+
+    def __set__(self, instance, value):
+        raise AttributeError("can't set attribute")
+
+    def __delete__(self, instance):
+        raise AttributeError("can't delete attribute")
+
+
+class PandasDelegate(object):
+    """ an abstract base class for delegating methods/properties """
+
+    @classmethod
+    def _make_accessor(cls, data):
+        raise AbstractMethodError("_make_accessor should be implemented"
+                                  "by subclass and return an instance"
+                                  "of `cls`.")
+
+    def _delegate_property_get(self, name, *args, **kwargs):
+        raise TypeError("You cannot access the "
+                        "property {name}".format(name=name))
+
+    def _delegate_property_set(self, name, value, *args, **kwargs):
+        raise TypeError("The property {name} cannot be set".format(name=name))
+
+    def _delegate_method(self, name, *args, **kwargs):
+        raise TypeError("You cannot call method {name}".format(name=name))
+
+    @classmethod
+    def _add_delegate_accessors(cls, delegate, accessors, typ,
+                                overwrite=False):
+        """
+        add accessors to cls from the delegate class
+
+        Parameters
+        ----------
+        cls : the class to add the methods/properties to
+        delegate : the class to get methods/properties & doc-strings
+        acccessors : string list of accessors to add
+        typ : 'property' or 'method'
+        overwrite : boolean, default False
+           overwrite the method/property in the target class if it exists
+        """
+
+        def _create_delegator_property(name):
+
+            def _getter(self):
+                return self._delegate_property_get(name)
+
+            def _setter(self, new_values):
+                return self._delegate_property_set(name, new_values)
+
+            _getter.__name__ = name
+            _setter.__name__ = name
+
+            return property(fget=_getter, fset=_setter,
+                            doc=getattr(delegate, name).__doc__)
+
+        def _create_delegator_method(name):
+
+            def f(self, *args, **kwargs):
+                return self._delegate_method(name, *args, **kwargs)
+
+            f.__name__ = name
+            f.__doc__ = getattr(delegate, name).__doc__
+
+            return f
+
+        for name in accessors:
+
+            if typ == 'property':
+                f = _create_delegator_property(name)
+            else:
+                f = _create_delegator_method(name)
+
+            # don't overwrite existing methods/properties
+            if overwrite or not hasattr(cls, name):
+                setattr(cls, name, f)

pandas/core/base.py

@@ -153,100 +153,6 @@ def __setattr__(self, key, value):
         object.__setattr__(self, key, value)
 
 
-class PandasDelegate(PandasObject):
-    """ an abstract base class for delegating methods/properties """
-
-    @classmethod
-    def _make_accessor(cls, data):
-        raise AbstractMethodError("_make_accessor should be implemented"
-                                  "by subclass and return an instance"
-                                  "of `cls`.")
-
-    def _delegate_property_get(self, name, *args, **kwargs):
-        raise TypeError("You cannot access the "
-                        "property {name}".format(name=name))
-
-    def _delegate_property_set(self, name, value, *args, **kwargs):
-        raise TypeError("The property {name} cannot be set".format(name=name))
-
-    def _delegate_method(self, name, *args, **kwargs):
-        raise TypeError("You cannot call method {name}".format(name=name))
-
-    @classmethod
-    def _add_delegate_accessors(cls, delegate, accessors, typ,
-                                overwrite=False):
-        """
-        add accessors to cls from the delegate class
-
-        Parameters
-        ----------
-        cls : the class to add the methods/properties to
-        delegate : the class to get methods/properties & doc-strings
-        acccessors : string list of accessors to add
-        typ : 'property' or 'method'
-        overwrite : boolean, default False
-           overwrite the method/property in the target class if it exists
-        """
-
-        def _create_delegator_property(name):
-
-            def _getter(self):
-                return self._delegate_property_get(name)
-
-            def _setter(self, new_values):
-                return self._delegate_property_set(name, new_values)
-
-            _getter.__name__ = name
-            _setter.__name__ = name
-
-            return property(fget=_getter, fset=_setter,
-                            doc=getattr(delegate, name).__doc__)
-
-        def _create_delegator_method(name):
-
-            def f(self, *args, **kwargs):
-                return self._delegate_method(name, *args, **kwargs)
-
-            f.__name__ = name
-            f.__doc__ = getattr(delegate, name).__doc__
-
-            return f
-
-        for name in accessors:
-
-            if typ == 'property':
-                f = _create_delegator_property(name)
-            else:
-                f = _create_delegator_method(name)
-
-            # don't overwrite existing methods/properties
-            if overwrite or not hasattr(cls, name):
-                setattr(cls, name, f)
-
-
-class AccessorProperty(object):
-    """Descriptor for implementing accessor properties like Series.str
-    """
-
-    def __init__(self, accessor_cls, construct_accessor=None):
-        self.accessor_cls = accessor_cls
-        self.construct_accessor = (construct_accessor or
-                                   accessor_cls._make_accessor)
-        self.__doc__ = accessor_cls.__doc__
-
-    def __get__(self, instance, owner=None):
-        if instance is None:
-            # this ensures that Series.str.<method> is well defined
-            return self.accessor_cls
-        return self.construct_accessor(instance)
-
-    def __set__(self, instance, value):
-        raise AttributeError("can't set attribute")
-
-    def __delete__(self, instance):
-        raise AttributeError("can't delete attribute")
-
-
 class GroupByError(Exception):
     pass
 

pandas/core/categorical.py

@@ -30,7 +30,8 @@
 from pandas.core.common import is_null_slice, _maybe_box_datetimelike
 
 from pandas.core.algorithms import factorize, take_1d, unique1d
-from pandas.core.base import (PandasObject, PandasDelegate,
+from pandas.core.accessor import PandasDelegate
+from pandas.core.base import (PandasObject,
                               NoNewAttributesMixin, _shared_docs)
 import pandas.core.common as com
 from pandas.core.missing import interpolate_2d
@@ -2065,7 +2066,7 @@ def repeat(self, repeats, *args, **kwargs):
 # The Series.cat accessor
 
 
-class CategoricalAccessor(PandasDelegate, NoNewAttributesMixin):
+class CategoricalAccessor(PandasDelegate, PandasObject, NoNewAttributesMixin):
     """
     Accessor object for categorical properties of the Series values.
 

pandas/core/frame.py

@@ -90,7 +90,7 @@
 from pandas.core.indexes.datetimes import DatetimeIndex
 from pandas.core.indexes.timedeltas import TimedeltaIndex
 
-import pandas.core.base as base
+from pandas.core import accessor
 import pandas.core.common as com
 import pandas.core.nanops as nanops
 import pandas.core.ops as ops
@@ -5897,7 +5897,8 @@ def isin(self, values):
 
     # ----------------------------------------------------------------------
     # Add plotting methods to DataFrame
-    plot = base.AccessorProperty(gfx.FramePlotMethods, gfx.FramePlotMethods)
+    plot = accessor.AccessorProperty(gfx.FramePlotMethods,
+                                     gfx.FramePlotMethods)
     hist = gfx.hist_frame
     boxplot = gfx.boxplot_frame
 

pandas/core/indexes/accessors.py

@@ -11,7 +11,8 @@
     is_timedelta64_dtype, is_categorical_dtype,
     is_list_like)
 
-from pandas.core.base import PandasDelegate, NoNewAttributesMixin
+from pandas.core.accessor import PandasDelegate
+from pandas.core.base import NoNewAttributesMixin, PandasObject
 from pandas.core.indexes.datetimes import DatetimeIndex
 from pandas._libs.period import IncompatibleFrequency  # noqa
 from pandas.core.indexes.period import PeriodIndex
@@ -81,7 +82,7 @@ def maybe_to_datetimelike(data, copy=False):
                     "datetimelike index".format(type(data)))
 
 
-class Properties(PandasDelegate, NoNewAttributesMixin):
+class Properties(PandasDelegate, PandasObject, NoNewAttributesMixin):
 
     def __init__(self, values, index, name, orig=None):
         self.values = values

pandas/core/indexes/base.py

@@ -57,7 +57,7 @@
 import pandas.core.sorting as sorting
 from pandas.io.formats.printing import pprint_thing
 from pandas.core.ops import _comp_method_OBJECT_ARRAY
-from pandas.core import strings
+from pandas.core import strings, accessor
 from pandas.core.config import get_option
 
 
@@ -159,7 +159,7 @@ class Index(IndexOpsMixin, PandasObject):
     _accessors = frozenset(['str'])
 
     # String Methods
-    str = base.AccessorProperty(strings.StringMethods)
+    str = accessor.AccessorProperty(strings.StringMethods)
 
     def __new__(cls, data=None, dtype=None, copy=False, name=None,
                 fastpath=False, tupleize_cols=True, **kwargs):

pandas/core/indexes/category.py

@@ -19,6 +19,7 @@
 from pandas.util._decorators import Appender, cache_readonly
 from pandas.core.config import get_option
 from pandas.core.indexes.base import Index, _index_shared_docs
+from pandas.core import accessor
 import pandas.core.base as base
 import pandas.core.missing as missing
 import pandas.core.indexes.base as ibase
@@ -27,7 +28,7 @@
 _index_doc_kwargs.update(dict(target_klass='CategoricalIndex'))
 
 
-class CategoricalIndex(Index, base.PandasDelegate):
+class CategoricalIndex(Index, accessor.PandasDelegate):
     """
 
     Immutable Index implementing an ordered, sliceable set. CategoricalIndex

pandas/core/series.py

@@ -62,6 +62,7 @@
 from pandas.compat import zip, u, OrderedDict, StringIO
 from pandas.compat.numpy import function as nv
 
+from pandas.core import accessor
 import pandas.core.ops as ops
 import pandas.core.algorithms as algorithms
 
@@ -2901,19 +2902,19 @@ def to_period(self, freq=None, copy=True):
 
     # -------------------------------------------------------------------------
     # Datetimelike delegation methods
-    dt = base.AccessorProperty(CombinedDatetimelikeProperties)
+    dt = accessor.AccessorProperty(CombinedDatetimelikeProperties)
 
     # -------------------------------------------------------------------------
     # Categorical methods
-    cat = base.AccessorProperty(CategoricalAccessor)
+    cat = accessor.AccessorProperty(CategoricalAccessor)
 
     # String Methods
-    str = base.AccessorProperty(strings.StringMethods)
+    str = accessor.AccessorProperty(strings.StringMethods)
 
     # ----------------------------------------------------------------------
     # Add plotting methods to Series
-    plot = base.AccessorProperty(gfx.SeriesPlotMethods,
-                                 gfx.SeriesPlotMethods)
+    plot = accessor.AccessorProperty(gfx.SeriesPlotMethods,
+                                     gfx.SeriesPlotMethods)
     hist = gfx.hist_series
 
 

pandas/tests/test_base.py

@@ -18,7 +18,8 @@
                     CategoricalIndex, Timestamp)
 from pandas.compat import StringIO, PYPY, long
 from pandas.compat.numpy import np_array_datetime64_compat
-from pandas.core.base import PandasDelegate, NoNewAttributesMixin
+from pandas.core.accessor import PandasDelegate
+from pandas.core.base import PandasObject, NoNewAttributesMixin
 from pandas.core.indexes.datetimelike import DatetimeIndexOpsMixin
 from pandas._libs.tslib import iNaT
 
@@ -105,7 +106,7 @@ def bar(self, *args, **kwargs):
             """ a test bar method """
             pass
 
-    class Delegate(PandasDelegate):
+    class Delegate(PandasDelegate, PandasObject):
 
         def __init__(self, obj):
             self.obj = obj