Enable python 3.5.0-3.5.2 (#2831)

* bump minimum python version to 3.5.3

* Revert "bump minimum python version to 3.5.3"

This reverts commit 77553e1.

* guard typing import block

* attempt to set patch version to 3.5.0

* "Type" also needs a guard

* move 3.5.0 to py35-min

* guiard all TYPE_CHECKING with new global

* missing import

* when two lines become one

* formatting

* two steps forward, one step back

* Consolidate variables

* lint

Author: max-sixty

ci/requirements-py35-min.yml

@@ -1,6 +1,6 @@
 name: test_env
 dependencies:
-  - python=3.5
+  - python=3.5.0
   - pytest
   - flake8
   - mock

xarray/coding/cftime_offsets.py

@@ -41,15 +41,19 @@
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 import re
+import typing
 from datetime import timedelta
 from functools import partial
-from typing import ClassVar, Optional
 
 import numpy as np
 
+from ..core.pycompat import TYPE_CHECKING
 from .cftimeindex import CFTimeIndex, _parse_iso8601_with_reso
 from .times import format_cftime_datetime
 
+if TYPE_CHECKING:
+    from typing import ClassVar, Optional
+
 
 def get_date_type(calendar):
     """Return the cftime date type for a given calendar name."""

xarray/core/computation.py

@@ -4,21 +4,22 @@
 import functools
 import itertools
 import operator
+import typing
 from collections import Counter, OrderedDict
 from distutils.version import LooseVersion
 from typing import (
     AbstractSet, Any, Callable, Iterable, List, Mapping, Optional, Sequence,
-    Tuple, TYPE_CHECKING, Union,
-)
+    Tuple, Union)
 
 import numpy as np
 
 from . import duck_array_ops, utils
 from .alignment import deep_align
 from .merge import expand_and_merge_variables
-from .pycompat import dask_array_type
+from .pycompat import TYPE_CHECKING, dask_array_type
 from .utils import is_dict_like
 from .variable import Variable
+
 if TYPE_CHECKING:
     from .dataset import Dataset
 

xarray/core/dataarray.py

@@ -5,9 +5,9 @@
 import numpy as np
 import pandas as pd
 
+from ..plot.plot import _PlotMethods
 from . import (
     computation, dtypes, groupby, indexing, ops, resample, rolling, utils)
-from ..plot.plot import _PlotMethods
 from .accessors import DatetimeAccessor
 from .alignment import align, reindex_like_indexers
 from .common import AbstractArray, DataWithCoords

xarray/core/dataset.py

@@ -1,45 +1,44 @@
 import copy
 import functools
 import sys
+import typing
 import warnings
 from collections import OrderedDict, defaultdict
 from collections.abc import Mapping
 from distutils.version import LooseVersion
 from numbers import Number
 from typing import (
-    Any, Callable, Dict, List, Optional, Set, Tuple, TypeVar, TYPE_CHECKING,
-    Union,
-)
+    Any, Callable, Dict, List, Optional, Set, Tuple, TypeVar, Union)
 
 import numpy as np
 import pandas as pd
 
 import xarray as xr
 
+from ..coding.cftimeindex import _parse_array_of_cftime_strings
 from . import (
     alignment, dtypes, duck_array_ops, formatting, groupby, indexing, ops,
     pdcompat, resample, rolling, utils)
-from ..coding.cftimeindex import _parse_array_of_cftime_strings
 from .alignment import align
 from .common import (
     ALL_DIMS, DataWithCoords, ImplementsDatasetReduce,
     _contains_datetime_like_objects)
 from .coordinates import (
     DatasetCoordinates, LevelCoordinatesSource, assert_coordinate_consistent,
-    remap_label_indexers,
-)
+    remap_label_indexers)
 from .duck_array_ops import datetime_to_numeric
 from .indexes import Indexes, default_indexes, isel_variable_and_index
 from .merge import (
     dataset_merge_method, dataset_update_method, merge_data_and_coords,
     merge_variables)
 from .options import OPTIONS, _get_keep_attrs
-from .pycompat import dask_array_type
+from .pycompat import TYPE_CHECKING, dask_array_type
 from .utils import (
-    Frozen, SortedKeysDict, _check_inplace,
-    decode_numpy_dict_values, either_dict_or_kwargs, ensure_us_time_resolution,
-    hashable, maybe_wrap_array)
+    Frozen, SortedKeysDict, _check_inplace, decode_numpy_dict_values,
+    either_dict_or_kwargs, ensure_us_time_resolution, hashable, is_dict_like,
+    maybe_wrap_array)
 from .variable import IndexVariable, Variable, as_variable, broadcast_variables
+
 if TYPE_CHECKING:
     from .dataarray import DataArray
 

xarray/core/merge.py

@@ -1,18 +1,19 @@
+import typing
 from collections import OrderedDict
-
-from typing import (
-    Any, Dict, List, Mapping, Optional, Set, Tuple, TYPE_CHECKING, Union,
-)
+from typing import Any, Dict, List, Mapping, Optional, Set, Tuple, Union
 
 import pandas as pd
 
 from .alignment import deep_align
+from .pycompat import TYPE_CHECKING
 from .utils import Frozen
 from .variable import (
     Variable, as_variable, assert_unique_multiindex_level_names)
+
 if TYPE_CHECKING:
     from .dataset import Dataset
 
+
 PANDAS_TYPES = (pd.Series, pd.DataFrame, pd.Panel)
 
 _VALID_COMPAT = Frozen({'identical': 0,

xarray/core/pycompat.py

@@ -1,4 +1,6 @@
 # flake8: noqa
+import sys
+import typing
 
 import numpy as np
 
@@ -10,3 +12,7 @@
     dask_array_type = (dask.array.Array,)
 except ImportError:  # pragma: no cover
     dask_array_type = ()
+
+# Ensure we have some more recent additions to the typing module.
+# Note that TYPE_CHECKING itself is not available on Python 3.5.1.
+TYPE_CHECKING = sys.version >= '3.5.3' and typing.TYPE_CHECKING

xarray/core/variable.py

@@ -1,8 +1,8 @@
 import functools
 import itertools
+import typing
 from collections import OrderedDict, defaultdict
 from datetime import timedelta
-from typing import Tuple, Type, Union
 
 import numpy as np
 import pandas as pd
@@ -15,9 +15,14 @@
     BasicIndexer, OuterIndexer, PandasIndexAdapter, VectorizedIndexer,
     as_indexable)
 from .options import _get_keep_attrs
-from .pycompat import dask_array_type, integer_types
-from .utils import (OrderedSet, either_dict_or_kwargs,
-                    decode_numpy_dict_values, ensure_us_time_resolution)
+from .pycompat import TYPE_CHECKING, dask_array_type, integer_types
+from .utils import (
+    OrderedSet, decode_numpy_dict_values, either_dict_or_kwargs,
+    ensure_us_time_resolution)
+
+if TYPE_CHECKING:
+    from typing import Tuple, Type, Union
+
 
 try:
     import dask.array as da