get_options return type to FrozenDict and added retention test

Author: pkopparla

xarray/core/options.py

@@ -1,5 +1,7 @@
 import warnings
 
+from .utils import FrozenDict
+
 ARITHMETIC_JOIN = "arithmetic_join"
 CMAP_DIVERGENT = "cmap_divergent"
 CMAP_SEQUENTIAL = "cmap_sequential"
@@ -250,4 +252,4 @@ def get_options():
       expand, ``False`` to always collapse, or ``default`` to expand unless over
       a pre-defined limit. Default: ``default``.
     """
-    return OPTIONS
+    return FrozenDict(OPTIONS)

xarray/tests/test_options.py

@@ -203,3 +203,10 @@ def test_display_dataarray_style_html(self):
             html = da._repr_html_()
             assert html.startswith("<div>")
             assert "#x27;nested&#x27;" in html
+
+
+def test_get_options_retention():
+    """Test to check if get_options will return changes made by set_options"""
+    with xarray.set_options(arithmetic_join="left"):
+        get_options = xarray.get_options()
+        assert get_options["arithmetic_join"] == "left"