Refactor compatibility modules into xarray.compat package (pydata#10131)

Start of pydata#10089

Move compatibility-related modules from xarray.core to new xarray.compat package:
- array_api_compat.py
- dask_array_compat.py
- dask_array_ops.py
- npcompat.py
- pdcompat.py

Author: max-sixty

xarray/coding/cftime_offsets.py

@@ -61,11 +61,11 @@
     convert_time_or_go_back,
     format_cftime_datetime,
 )
-from xarray.core.common import _contains_datetime_like_objects, is_np_datetime_like
-from xarray.core.pdcompat import (
+from xarray.compat.pdcompat import (
     count_not_none,
     default_precision_timestamp,
 )
+from xarray.core.common import _contains_datetime_like_objects, is_np_datetime_like
 from xarray.core.types import InclusiveOptions
 from xarray.core.utils import attempt_import, emit_user_level_warning
 

xarray/coding/times.py

@@ -20,11 +20,11 @@
     unpack_for_decoding,
     unpack_for_encoding,
 )
+from xarray.compat.pdcompat import default_precision_timestamp, timestamp_as_unit
 from xarray.core import indexing
 from xarray.core.common import contains_cftime_datetimes, is_np_datetime_like
 from xarray.core.duck_array_ops import array_all, array_any, asarray, ravel, reshape
 from xarray.core.formatting import first_n_items, format_timestamp, last_item
-from xarray.core.pdcompat import default_precision_timestamp, timestamp_as_unit
 from xarray.core.utils import attempt_import, emit_user_level_warning
 from xarray.core.variable import Variable
 from xarray.namedarray.parallelcompat import T_ChunkedArray, get_chunked_array_type

xarray/compat/__init__.py

@@ -2,6 +2,7 @@
 
 import math
 
+from xarray.compat.dask_array_compat import reshape_blockwise
 from xarray.core import dtypes, nputils
 
 
@@ -21,8 +22,6 @@ def dask_rolling_wrapper(moving_func, a, window, min_count=None, axis=-1):
 def least_squares(lhs, rhs, rcond=None, skipna=False):
     import dask.array as da
 
-    from xarray.core.dask_array_compat import reshape_blockwise
-
     # The trick here is that the core dimension is axis 0.
     # All other dimensions need to be reshaped down to one axis for `lstsq`
     # (which only accepts 2D input)

xarray/core/array_api_compat.py renamed to xarray/compat/array_api_compat.py

@@ -22,9 +22,9 @@
 
 import numpy as np
 
+from xarray.compat.array_api_compat import to_like_array
 from xarray.core import dtypes, duck_array_ops, utils
 from xarray.core.alignment import align, deep_align
-from xarray.core.array_api_compat import to_like_array
 from xarray.core.common import zeros_like
 from xarray.core.duck_array_ops import datetime_to_numeric
 from xarray.core.formatting import limit_lines

xarray/core/dask_array_compat.py renamed to xarray/compat/dask_array_compat.py

@@ -41,6 +41,7 @@
 
 from xarray.coding.calendar_ops import convert_calendar, interp_calendar
 from xarray.coding.cftimeindex import CFTimeIndex, _parse_array_of_cftime_strings
+from xarray.compat.array_api_compat import to_like_array
 from xarray.core import (
     alignment,
     duck_array_ops,
@@ -57,7 +58,6 @@
     align,
 )
 from xarray.core.arithmetic import DatasetArithmetic
-from xarray.core.array_api_compat import to_like_array
 from xarray.core.common import (
     DataWithCoords,
     _contains_datetime_like_objects,