StringDtype data type not understood

Question

When converting from an extension type, eg pd.Int32Dtype() , I get TypeError: data type not understood . Example:

num_col_with_nan = num_col_with_nan.astype(pd.Int32Dtype()).astype("string")

Answer 1

Casting between extension types is not yet supported - see #22384 for general overview and #31204 for StringDtype in particular.

As a workaround, try casting to str first:

num_col_with_nan = num_col_with_nan.astype(pd.Int32Dtype()).astype(str).astype("string")