I have the following df data frame in pandas:
weekday venta_total_cy 0 Viernes 5.430211e+09 1 Lunes 3.425554e+09 2 Sabado 6.833202e+09 3 Domingo 6.566466e+09 4 Jueves 2.748710e+09 5 Martes 3.328418e+09 6 Miercoles 3.136277e+09
What I want to do is to order the data frame by the following days’ order:
weekday Lunes Martes Miercoles Jueves Viernes Sabado Domingo
To do so, I used the following code:
df['weekday'] = pd.Categorical(df[['weekday']], categories=["Lunes", "Martes", "Miercoles", "Jueves", "Viernes", "Sabado", "Domingo"])
When I run the code, I get this error:
ValueError: Cannot setitem on a Categorical with a new category, set the categories first
I have not found enough documentation to resolve this. Can you help me? Thanks!
Advertisement
Answer
df[['weekday']]
returns a dataframe, which is incorrect. Convert the series column to categorical instead. Also, use the ordered=True
argument to establish order in your categorical column.
categories = np.array( ['Lunes', 'Martes', 'Miercoles', 'Jueves', 'Viernes', 'Sabado', 'Domingo']) df['weekday'] = pd.Categorical( df['weekday'], categories=categories, ordered=True) df.sort_values(by='weekday') weekday venta_total_cy 1 Lunes 3.425554e+09 5 Martes 3.328418e+09 6 Miercoles 3.136277e+09 4 Jueves 2.748710e+09 0 Viernes 5.430211e+09 2 Sabado 6.833202e+09 3 Domingo 6.566466e+09