How can I sort DataFrame in Python on 1st variable in ascending, on 2nd variable in custom order and on 3rd variable in Descending

Question

How can I sort below DataFrame in this Priority order

1) 'Seller_id' in ascending

2) 'Months' on basis of Custom_ordering = ['Jan', 'Feb', 'Mar', 'Apr', 'May']

3) 'Sales_amount' in descending

df = pd.DataFrame({
                'Seller_id': [121,121,121,121,121,121,
                              321,321,321,321,321,321,
                              597,597,597,597,597,597],
                'Months': ['Feb', 'Jan', 'Mar', 'May', 'Apr','Mar',
                          'Jan', 'Feb', 'Mar', 'Apr', 'May','Feb',
                          'Jan', 'Feb', 'Mar', 'Apr', 'May','Jan'],
                'Sales_amount': [100,87,95,105,100,100,
                                100,87,95,105,110,105,
                                100,105,95,100,110,105]

})

Custom_ordering = ['Jan', 'Feb', 'Mar', 'Apr', 'May']

Expected Output

Seller_id   Months  Sales_amount
0   121 Jan 87
1   121 Feb 100
2   121 Mar 100
3   121 Mar 95
4   121 Apr 100
5   121 May 105
6   321 Jan 100
7   321 Feb 105
8   321 Feb 87
9   321 Mar 95
10  321 Apr 105
11  321 May 110
12  597 Jan 105
13  597 Jan 100
14  597 Feb 105
15  597 Mar 95
16  597 Apr 100
17  597 May 110

Answer 1

First convert Months to categorical using pd.Categorical :

df['Months'] = pd.Categorical(df['Months'], categories = ['Jan', 'Feb', 'Mar', 'Apr', 'May'], ordered = False)

Now do:

df.sort_values(['Seller_id', 'Months', 'Sales_amount'], ascending = [True, True, False])