Extraneous parts broken off from other DTA/TDA PRs

pandas/core/arrays/datetimelike.py

@@ -12,7 +12,8 @@
 from pandas._libs.tslibs.period import (
     Period, DIFFERENT_FREQ_INDEX, IncompatibleFrequency)
 
-from pandas.errors import NullFrequencyError, PerformanceWarning
+from pandas.errors import (
+    AbstractMethodError, NullFrequencyError, PerformanceWarning)
 from pandas import compat
 
 from pandas.tseries import frequencies
@@ -78,12 +79,10 @@ class AttributesMixin(object):
     @property
     def _attributes(self):
         # Inheriting subclass should implement _attributes as a list of strings
-        from pandas.errors import AbstractMethodError
         raise AbstractMethodError(self)
 
     @classmethod
     def _simple_new(cls, values, **kwargs):
-        from pandas.errors import AbstractMethodError
         raise AbstractMethodError(cls)
 
     def _get_attributes_dict(self):
@@ -108,7 +107,7 @@ def _box_func(self):
         """
         box function to get object from internal representation
         """
-        raise com.AbstractMethodError(self)
+        raise AbstractMethodError(self)
 
     def _box_values(self, values):
         """
@@ -337,7 +336,7 @@ def _sub_period(self, other):
                         .format(cls=type(self).__name__))
 
     def _add_offset(self, offset):
-        raise com.AbstractMethodError(self)
+        raise AbstractMethodError(self)
 
     def _add_delta(self, other):
         """

pandas/core/arrays/datetimes.py

@@ -170,6 +170,8 @@ class DatetimeArrayMixin(dtl.DatetimeLikeArrayMixin):
     # Constructors
 
     _attributes = ["freq", "tz"]
+    _tz = None
+    _freq = None
 
     @classmethod
     def _simple_new(cls, values, freq=None, tz=None, **kwargs):

pandas/core/arrays/period.py

@@ -165,7 +165,10 @@ class PeriodArray(dtl.DatetimeLikeArrayMixin, ExtensionArray):
 
     # --------------------------------------------------------------------
     # Constructors
-    def __init__(self, values, freq=None, copy=False):
+
+    def __init__(self, values, freq=None, dtype=None, copy=False):
+        freq = dtl.validate_dtype_freq(dtype, freq)
+
         if freq is not None:
             freq = Period._maybe_convert_freq(freq)
 

pandas/core/indexes/datetimes.py

@@ -182,7 +182,6 @@ class DatetimeIndex(DatetimeArrayMixin, DatelikeOps, TimelikeOps,
 
     """
     _resolution = cache_readonly(DatetimeArrayMixin._resolution.fget)
-    _shallow_copy = Index._shallow_copy
 
     _typ = 'datetimeindex'
     _join_precedence = 10
@@ -199,11 +198,15 @@ def _join_i8_wrapper(joinf, **kwargs):
 
     _engine_type = libindex.DatetimeEngine
 
-    tz = None
+    _tz = None
     _freq = None
     _comparables = ['name', 'freqstr', 'tz']
     _attributes = ['name', 'freq', 'tz']
 
+    # dummy attribute so that datetime.__eq__(DatetimeArray) defers
+    # by returning NotImplemented
+    timetuple = None
+
     # define my properties & methods for delegation
     _bool_ops = ['is_month_start', 'is_month_end',
                  'is_quarter_start', 'is_quarter_end', 'is_year_start',
@@ -226,6 +229,9 @@ def _join_i8_wrapper(joinf, **kwargs):
     _timezone = cache_readonly(DatetimeArrayMixin._timezone.fget)
     is_normalized = cache_readonly(DatetimeArrayMixin.is_normalized.fget)
 
+    # --------------------------------------------------------------------
+    # Constructors
+
     def __new__(cls, data=None,
                 freq=None, start=None, end=None, periods=None, tz=None,
                 normalize=False, closed=None, ambiguous='raise',
@@ -280,7 +286,7 @@ def __new__(cls, data=None,
                 data = data.tz_localize(tz, ambiguous=ambiguous)
             else:
                 # the tz's must match
-                if str(tz) != str(data.tz):
+                if not timezones.tz_compare(tz, data.tz):
                     msg = ('data is already tz-aware {0}, unable to '
                            'set specified tz: {1}')
                     raise TypeError(msg.format(data.tz, tz))
@@ -327,12 +333,6 @@ def __new__(cls, data=None,
 
         return subarr._deepcopy_if_needed(ref_to_data, copy)
 
-    def _convert_for_op(self, value):
-        """ Convert value to be insertable to ndarray """
-        if self._has_same_tz(value):
-            return _to_m8(value)
-        raise ValueError('Passed item and index have different timezone')
-
     @classmethod
     def _simple_new(cls, values, name=None, freq=None, tz=None,
                     dtype=None, **kwargs):
@@ -349,6 +349,8 @@ def _simple_new(cls, values, name=None, freq=None, tz=None,
         result._reset_identity()
         return result
 
+    # --------------------------------------------------------------------
+
     @property
     def _values(self):
         # tz-naive -> ndarray
@@ -448,6 +450,12 @@ def __setstate__(self, state):
             raise Exception("invalid pickle state")
     _unpickle_compat = __setstate__
 
+    def _convert_for_op(self, value):
+        """ Convert value to be insertable to ndarray """
+        if self._has_same_tz(value):
+            return _to_m8(value)
+        raise ValueError('Passed item and index have different timezone')
+
     def _maybe_update_attributes(self, attrs):
         """ Update Index attributes (e.g. freq) depending on op """
         freq = attrs.get('freq', None)
@@ -1104,6 +1112,9 @@ def slice_indexer(self, start=None, end=None, step=None, kind=None):
             else:
                 raise
 
+    # --------------------------------------------------------------------
+    # Wrapping DatetimeArray
+
     year = wrap_field_accessor(DatetimeArrayMixin.year)
     month = wrap_field_accessor(DatetimeArrayMixin.month)
     day = wrap_field_accessor(DatetimeArrayMixin.day)
@@ -1142,6 +1153,8 @@ def slice_indexer(self, start=None, end=None, step=None, kind=None):
     month_name = wrap_array_method(DatetimeArrayMixin.month_name, True)
     day_name = wrap_array_method(DatetimeArrayMixin.day_name, True)
 
+    # --------------------------------------------------------------------
+
     @Substitution(klass='DatetimeIndex')
     @Appender(_shared_docs['searchsorted'])
     def searchsorted(self, value, side='left', sorter=None):

pandas/core/indexes/timedeltas.py

@@ -209,8 +209,6 @@ def _simple_new(cls, values, name=None, freq=None, dtype=_TD_DTYPE):
         result._reset_identity()
         return result
 
-    _shallow_copy = Index._shallow_copy
-
     @property
     def _formatter_func(self):
         from pandas.io.formats.format import _get_format_timedelta64
@@ -243,13 +241,18 @@ def _format_native_types(self, na_rep=u'NaT', date_format=None, **kwargs):
                                     nat_rep=na_rep,
                                     justify='all').get_result()
 
+    # -------------------------------------------------------------------
+    # Wrapping TimedeltaArray
+
     days = wrap_field_accessor(TimedeltaArrayMixin.days)
     seconds = wrap_field_accessor(TimedeltaArrayMixin.seconds)
     microseconds = wrap_field_accessor(TimedeltaArrayMixin.microseconds)
     nanoseconds = wrap_field_accessor(TimedeltaArrayMixin.nanoseconds)
 
     total_seconds = wrap_array_method(TimedeltaArrayMixin.total_seconds, True)
 
+    # -------------------------------------------------------------------
+
     @Appender(_index_shared_docs['astype'])
     def astype(self, dtype, copy=True):
         dtype = pandas_dtype(dtype)