Unfill in Multiple Columns - Excel, Power Query and Python in Excel

Remove repeated consecutive values in Qtr and Month Column.

The opposite operation to the Fill Down approach.

Workbook Link:

https://1drv.ms/x/c/a0ca510549929b21/IQBEM8uCS0QqS7nuLSC0vbOuAfKujE7raDGz38_Ocmy3gJw?e=4NH0wV

Solution:

Excel:

=HSTACK(MAP(B2:C14,LAMBDA(x,IF(COUNTIF(TAKE(B2:x,,-1),x)=1,x,""))),D2:D14)

Power Query:

let

 Source = Excel.CurrentWorkbook(){[Name="Table1"]}[Content],

 Result = Table.FromColumns(List.Transform(Table.ToColumns(Source[[Qtr],[Month]]), (f) => List.Accumulate( List.Skip(f), {f{0}}, (s,c) => s & {if List.Contains(s,c) then null else c})) & {Source[Sales]}, Table.ColumnNames(Source))

in

 Result

Python in Excel:

df = xl("B2:D14", headers=True)

df.mask(df.apply(lambda col: False if col.name == 'Sales' else col.duplicated()),'')