Order DataFrame By Group of Category as Window

Question

However I found several similar questions/answers, none demonstrated a "simple" manner to order a pandas dataframe by groups of categories and minimum value like window partitions. The image represents pretty well the goal.

data = {
    'Section': ['A', 'C', 'C', 'B', 'A', 'D', 'B', 'D'],
    'Content': [3, 5, 2, 3, 1, 1, 0, 2]
}

df_initial = pd.DataFrame(data)


data = {
    'Section': ['A', 'B', 'C', 'D', 'A', 'B', 'C', 'D'],
    'Content': [1, 0, 2, 1, 3, 3, 5, 2]
}

df_sorted = pd.DataFrame(data)

This example was the nearest one I found by keeping the whole group together

Ranking order per group in Pandas

Cheers

Answer 1

Try this:

df['sortkey'] = df.sort_values(['Content']).groupby('Section')['Content'].cumcount()
df.sort_values(['sortkey', 'Section'])

Output:

  Section  Content  sortkey
4       A        1        0
6       B        0        0
2       C        2        0
5       D        1        0
0       A        3        1
3       B        3        1
1       C        5        1
7       D        2        1

Details:

• Sort by Content first to order
• Groupby section and use cumcount to get order in each section
• Lastly, sort the dataframe first my the new created sortkey and section.
• You can drop sortkey add .drop('sortkey', axis=1)