BUG: setting categorical values into object dtype DataFrame by jbrockmendel · Pull Request #39136 · pandas-dev/pandas (original) (raw)

df = pd.DataFrame({"A": range(3)}, dtype=object)
cat = pd.Categorical(["alpha", "beta", "gamma"])

df.iloc[range(3), 0] = cat

>>> df
     A
0  NaN
1     
2