Add empty row with or without name:

df.append(pd.Series(name='NameOfNewRow')) # name the new row
df.append(pd.Series(), ignore_index=True) # not name the new row

Add empty column:

df['new'] = pd.Series()

Source:
https://stackoverflow.com/questions/39998262/append-an-empty-row-in-dataframe-using-pandas
https://stackoverflow.com/questions/16327055/how-to-add-an-empty-column-to-a-dataframe