CLN: unnecessary checks (#38467)

Author: jbrockmendel

pandas/core/arrays/categorical.py

@@ -321,7 +321,7 @@ def __init__(
  if is_categorical_dtype(values):
  if dtype.categories is None:
  dtype = CategoricalDtype(values.categories, dtype.ordered)
- elif not isinstance(values, (ABCIndex, ABCSeries)):
+ elif not isinstance(values, (ABCIndex, ABCSeries, ExtensionArray)):
  # sanitize_array coerces np.nan to a string under certain versions
  # of numpy
  values = maybe_infer_to_datetimelike(values, convert_dates=True)

pandas/core/dtypes/cast.py

@@ -80,11 +80,8 @@
 )
 from pandas.core.dtypes.generic import (
  ABCDataFrame,
- ABCDatetimeArray,
- ABCDatetimeIndex,
  ABCExtensionArray,
- ABCPeriodArray,
- ABCPeriodIndex,
+ ABCIndex,
  ABCSeries,
 )
 from pandas.core.dtypes.inference import is_list_like
@@ -1252,11 +1249,9 @@ def maybe_infer_to_datetimelike(
  leave inferred dtype 'date' alone
 
  """
- # TODO: why not timedelta?
- if isinstance(
- value, (ABCDatetimeIndex, ABCPeriodIndex, ABCDatetimeArray, ABCPeriodArray)
- ):
- return value
+ if isinstance(value, (ABCIndex, ABCExtensionArray)):
+ if not is_object_dtype(value.dtype):
+ raise ValueError("array-like value must be object-dtype")
 
  v = value
 
@@ -1431,7 +1426,7 @@ def maybe_cast_to_datetime(value, dtype: Optional[DtypeObj]):
  value = to_timedelta(value, errors="raise")._values
  except OutOfBoundsDatetime:
  raise
- except (AttributeError, ValueError, TypeError):
+ except (ValueError, TypeError):
  pass
 
  # coerce datetimelike to object

pandas/core/internals/construction.py

@@ -212,7 +212,7 @@ def init_ndarray(values, index, columns, dtype: Optional[DtypeObj], copy: bool):
  # if we don't have a dtype specified, then try to convert objects
  # on the entire block; this is to convert if we have datetimelike's
  # embedded in an object type
- if dtype is None and is_object_dtype(values):
+ if dtype is None and is_object_dtype(values.dtype):
 
  if values.ndim == 2 and values.shape[0] != 1:
  # transpose and separate blocks