code sample for pandas-dev#46812

Author: simonjayhawkins

bisect/46812.py

@@ -0,0 +1,22 @@
+# BUG: Error writing DataFrame with categorical type column and "Int" data to a CSV file ("int" works of course) #46812
+
+import numpy as np
+import pandas as pd
+
+print(pd.__version__)
+
+d = {
+    "name": ["bob", "todd", "sarah", "john"],
+    "gp": [1, 2, np.NaN, 2],
+    "score": [90, 40, 80, 98],
+}
+df = pd.DataFrame(d)
+df.name = df.name.astype("category")
+df.gp = df.gp.astype("Int16")
+df.gp = df.gp.astype("category")
+
+result = df.to_csv()
+print(result)
+
+expected = ",name,gp,score\n0,bob,1,90\n1,todd,2,40\n2,sarah,,80\n3,john,2,98\n"
+assert result == expected