implement maybe_validate_freq

pandas-dev · jbrockmendel · Nov 4, 2018 · Nov 4, 2018 · Nov 4, 2018 · Nov 4, 2018
commit 3a6263321d7740e6f8039a04a690e686a934fde7
diff --git a/pandas/core/arrays/datetimelike.py b/pandas/core/arrays/datetimelike.py
@@ -928,6 +928,26 @@ def maybe_define_freq(freq_infer, result):
             result.freq = frequencies.to_offset(inferred)
 
 
+def maybe_validate_freq(result, verify, freq, freq_infer, **kwargs):
+    """
+    If a frequency was passed by the user and not inferred or extracted
+    from the underlying data, then validate that the data is consistent with
+    the user-provided frequency.
+
+    Parameters
+    ----------
+    result : DatetimeIndex or TimedeltaIndex
+    verify : bool
+    freq : DateOffset or None
+    freq_infer : bool
+    **kwargs : arguments to pass to `_validate_frequency`
+        For DatetimeIndex this is just "ambiguous", empty for TimedeltaIndex
+    """
+    if verify and len(result) > 0:
+        if freq is not None and not freq_infer:
+            result._validate_frequency(result, freq, **kwargs)
+
+
 def validate_tz_from_dtype(dtype, tz):
     """
     If the given dtype is a DatetimeTZDtype, extract the implied

diff --git a/pandas/core/indexes/datetimes.py b/pandas/core/indexes/datetimes.py
@@ -309,11 +309,8 @@ def __new__(cls, data=None,
         assert subarr.dtype == 'M8[ns]', subarr.dtype
 
         subarr = cls._simple_new(subarr, name=name, freq=freq, tz=tz)
-
-        if verify_integrity and len(subarr) > 0:
-            if freq is not None and not freq_infer:
-                cls._validate_frequency(subarr, freq, ambiguous=ambiguous)
-
+        dtl.maybe_validate_freq(subarr, verify_integrity, freq, freq_infer,
+                                ambiguous=ambiguous)
         dtl.maybe_define_freq(freq_infer, subarr)
         return subarr._deepcopy_if_needed(ref_to_data, copy)
 

diff --git a/pandas/core/indexes/timedeltas.py b/pandas/core/indexes/timedeltas.py
@@ -174,11 +174,7 @@ def __new__(cls, data=None, unit=None, freq=None, start=None, end=None,
         assert data.dtype == 'm8[ns]', data.dtype
 
         subarr = cls._simple_new(data, name=name, freq=freq)
-        # check that we are matching freqs
-        if verify_integrity and len(subarr) > 0:
-            if freq is not None and not freq_infer:
-                cls._validate_frequency(subarr, freq)
-
+        dtl.maybe_validate_freq(subarr, verify_integrity, freq, freq_infer)
         dtl.maybe_define_freq(freq_infer, subarr)
         return subarr