I have the following df data frame in pandas:
JavaScript
x
9
1
weekday venta_total_cy2
0 Viernes 5.430211e+093
1 Lunes 3.425554e+094
2 Sabado 6.833202e+095
3 Domingo 6.566466e+096
4 Jueves 2.748710e+097
5 Martes 3.328418e+098
6 Miercoles 3.136277e+099
What I want to do is to order the data frame by the following days’ order:
JavaScript
1
9
1
weekday2
Lunes3
Martes4
Miercoles5
Jueves6
Viernes7
Sabado8
Domingo9
To do so, I used the following code:
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1
2
1
df['weekday'] = pd.Categorical(df[['weekday']], categories=["Lunes", "Martes", "Miercoles", "Jueves", "Viernes", "Sabado", "Domingo"])2
When I run the code, I get this error:
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1
2
1
ValueError: Cannot setitem on a Categorical with a new category, set the categories first2
I have not found enough documentation to resolve this. Can you help me? Thanks!
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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.
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16
16
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categories = np.array(2
['Lunes', 'Martes', 'Miercoles', 'Jueves', 'Viernes', 'Sabado', 'Domingo'])3
4
df['weekday'] = pd.Categorical(5
df['weekday'], categories=categories, ordered=True)6
df.sort_values(by='weekday')7
8
weekday venta_total_cy9
1 Lunes 3.425554e+0910
5 Martes 3.328418e+0911
6 Miercoles 3.136277e+0912
4 Jueves 2.748710e+0913
0 Viernes 5.430211e+0914
2 Sabado 6.833202e+0915
3 Domingo 6.566466e+0916