added classification enums to qp

Author: ESadek-MO

lib/iris/quickplot.py

@@ -8,12 +8,15 @@
 automatically add a plot title, axis titles, and a colour bar when appropriate.
 
 These also have the optional kwarg ``footer``, which adds text to the bottom right of
-the plot figure.
+the plot figure. For security classifications, the enum :class:`Classifications`
+can be used for common usages.
 
 See also: :ref:`matplotlib <matplotlib:users-guide-index>`.
 
 """
 
+from enum import StrEnum
+
 import cf_units
 from matplotlib import patheffects
 import matplotlib.pyplot as plt
@@ -23,6 +26,13 @@
 import iris.plot as iplt
 
 
+class Classification(StrEnum):
+    official = "Official"
+    official_sensitive = "Official-Sensitive"
+    secret = "Secret"
+    top_secret = "Top Secret"
+
+
 def _use_symbol(units):
     # For non-time units use the shortest unit representation.
     # E.g. prefer 'K' over 'kelvin', but not '0.0174532925199433 rad'

lib/iris/tests/test_quickplot.py

@@ -283,9 +283,11 @@ def test_vertical(self):
 
 @_shared_utils.skip_plot
 class TestFooter:
-    def test__footer(self):
-        text = "Example"
+    @pytest.mark.parametrize(
+        "text", [qplt.Classification.official_sensitive, "Example"]
+    )
+    def test__footer(self, text):
+        fig = plt.figure()
         qplt._footer(text)
-        fig = plt.gcf()
         footer_text = fig.texts[0].get_text()
         assert text == footer_text