Allow training of Series with tuples

closes has2k1/plotnine#933

Author: has2k1

doc/changelog.rst

@@ -1,6 +1,17 @@
 Changelog
 =========
 
+v0.13.3
+-------
+
+*2025-04-11*
+
+Enhancements
+************
+
+- Make it possible to train discrete data that is a sequence of tuples.
+  (plotnine issue [#933](https://github.com/has2k1/plotnine/issues/933))
+
 v0.13.2
 -------
 *2025-04-03*

mizani/scale.py

@@ -272,7 +272,7 @@ def train(
             limits = old + [i for i in new if (i not in old_set)]
 
         # Add nan if required
-        has_na_limits = any(pd.isna(limits))
+        has_na_limits = pd.isna(limits).any()
         if not has_na_limits and not na_rm and has_na:
             limits.append(np.nan)
         return limits

tests/test_scale.py

@@ -111,3 +111,10 @@ def SCategorical(*args, **kwargs):
     limits = scale_discrete.train(x2, old=limits)
     # assert limits == list('abcedf')
     assert limits == list("adefbc")
+
+    # Sequence of tuples
+    x1 = pd.Series([(1, 2), (3, 4), (5, 6)])
+    x2 = pd.Series([(1, 2), (7, 8)])
+    limits = scale_discrete.train(x1)
+    limits = scale_discrete.train(x2, old=limits)
+    assert limits == [(1, 2), (3, 4), (5, 6), (7, 8)]