Add typing_extensions as a required dependency

ci/requirements/environment-windows.yml

@@ -39,6 +39,7 @@ dependencies:
   - setuptools
   - sparse
   - toolz
+  - typing_extensions
   - zarr
   - pip:
     - numbagg

ci/requirements/environment.yml

@@ -43,6 +43,7 @@ dependencies:
   - setuptools
   - sparse
   - toolz
+  - typing_extensions
   - zarr
   - pip:
     - numbagg

ci/requirements/py37-bare-minimum.yml

@@ -13,3 +13,4 @@ dependencies:
   - numpy=1.17
   - pandas=1.0
   - setuptools=40.4
+  - typing_extensions=3.7

ci/requirements/py37-min-all-deps.yml

@@ -47,6 +47,7 @@ dependencies:
   - setuptools=40.4
   - sparse=0.8
   - toolz=0.10
+  - typing_extensions=3.7
   - zarr=2.4
   - pip:
     - numbagg==0.1

ci/requirements/py38-all-but-dask.yml

@@ -39,6 +39,7 @@ dependencies:
   - setuptools
   - sparse
   - toolz
+  - typing_extensions
   - zarr
   - pip:
     - numbagg

doc/getting-started-guide/installing.rst

@@ -8,6 +8,7 @@ Required dependencies
 
 - Python (3.7 or later)
 - setuptools (40.4 or later)
+- ``typing_extensions`` (3.7 or later)
 - `numpy <http://www.numpy.org/>`__ (1.17 or later)
 - `pandas <http://pandas.pydata.org/>`__ (1.0 or later)
 

requirements.txt

@@ -5,4 +5,4 @@
 numpy >= 1.17
 pandas >= 1.0
 setuptools >= 40.4
-typing-extensions >= 3.10
+typing-extensions >= 3.7

setup.cfg

@@ -78,6 +78,7 @@ python_requires = >=3.7
 install_requires =
     numpy >= 1.17
     pandas >= 1.0
+    typing_extensions >= 3.7
     setuptools >= 40.4  # For pkg_resources
 
 [options.extras_require]

xarray/core/npcompat.py

@@ -41,17 +41,10 @@
     # fall back for numpy < 1.20, ArrayLike adapted from numpy.typing._array_like
     if sys.version_info >= (3, 8):
         from typing import Protocol
-
-        HAVE_PROTOCOL = True
     else:
-        try:
-            from typing_extensions import Protocol
-        except ImportError:
-            HAVE_PROTOCOL = False
-        else:
-            HAVE_PROTOCOL = True
+        from typing_extensions import Protocol
 
-    if TYPE_CHECKING or HAVE_PROTOCOL:
+    if TYPE_CHECKING:
 
         class _SupportsArray(Protocol):
             def __array__(self) -> np.ndarray:

xarray/core/options.py

@@ -6,70 +6,35 @@
 # TODO: Remove this check once python 3.7 is not supported:
 if sys.version_info >= (3, 8):
     from typing import TYPE_CHECKING, Literal, TypedDict, Union
+else:
+    from typing import TYPE_CHECKING, Union
 
-    if TYPE_CHECKING:
-        try:
-            from matplotlib.colors import Colormap
-        except ImportError:
-            Colormap = str
-
-    class T_Options(TypedDict):
-        arithmetic_join: Literal["inner", "outer", "left", "right", "exact"]
-        cmap_divergent: Union[str, "Colormap"]
-        cmap_sequential: Union[str, "Colormap"]
-        display_max_rows: int
-        display_style: Literal["text", "html"]
-        display_width: int
-        display_expand_attrs: Literal["default", True, False]
-        display_expand_coords: Literal["default", True, False]
-        display_expand_data_vars: Literal["default", True, False]
-        display_expand_data: Literal["default", True, False]
-        enable_cftimeindex: bool
-        file_cache_maxsize: int
-        keep_attrs: Literal["default", True, False]
-        warn_for_unclosed_files: bool
-        use_bottleneck: bool
+    from typing_extensions import Literal, TypedDict
 
 
-else:
-    # See GH5624, this is a convoluted way to allow type-checking to use
-    # `TypedDict` and `Literal` without requiring typing_extensions as a
-    #  required dependency to _run_ the code (it is required to type-check).
+if TYPE_CHECKING:
     try:
-        from typing import TYPE_CHECKING, Union
-
-        from typing_extensions import Literal, TypedDict
-
-        if TYPE_CHECKING:
-            try:
-                from matplotlib.colors import Colormap
-            except ImportError:
-                Colormap = str
-
-        class T_Options(TypedDict):
-            arithmetic_join: Literal["inner", "outer", "left", "right", "exact"]
-            cmap_divergent: Union[str, "Colormap"]
-            cmap_sequential: Union[str, "Colormap"]
-            display_max_rows: int
-            display_style: Literal["text", "html"]
-            display_width: int
-            display_expand_attrs: Literal["default", True, False]
-            display_expand_coords: Literal["default", True, False]
-            display_expand_data_vars: Literal["default", True, False]
-            display_expand_data: Literal["default", True, False]
-            enable_cftimeindex: bool
-            file_cache_maxsize: int
-            keep_attrs: Literal["default", True, False]
-            warn_for_unclosed_files: bool
-            use_bottleneck: bool
-
+        from matplotlib.colors import Colormap
     except ImportError:
-        from typing import TYPE_CHECKING, Any, Dict, Hashable
-
-        if TYPE_CHECKING:
-            raise
-        else:
-            T_Options = Dict[Hashable, Any]
+        Colormap = str
+
+
+class T_Options(TypedDict):
+    arithmetic_join: Literal["inner", "outer", "left", "right", "exact"]
+    cmap_divergent: Union[str, "Colormap"]
+    cmap_sequential: Union[str, "Colormap"]
+    display_max_rows: int
+    display_style: Literal["text", "html"]
+    display_width: int
+    display_expand_attrs: Literal["default", True, False]
+    display_expand_coords: Literal["default", True, False]
+    display_expand_data_vars: Literal["default", True, False]
+    display_expand_data: Literal["default", True, False]
+    enable_cftimeindex: bool
+    file_cache_maxsize: int
+    keep_attrs: Literal["default", True, False]
+    warn_for_unclosed_files: bool
+    use_bottleneck: bool
 
 
 OPTIONS: T_Options = {