pandas.Series.str¶

1. The attribute pandas.Series.str can only be used with Series of str values. You will either encounter an AttributionError (Can only use .str accessor with string values, which use np.object_ dtype in pandas) or find it to yield a Series of NaN's if you invoke it on a Series of non-string values. If you have control of the DataFrame, the preferred way is to cast the type the column to str