# Tags **Software** : [[02 - Tags/Software/Power Query]] **Functions** used : [[Table.TransformColumnTypes]] [[List.Sum]] [[02 - Tags/Power Query Functions/List.Select]] [[Table.ColumnNames]] [[Text.Contains]] [[list.Accumulate]] [[Table.TransformColumns]] [[Table.Column]] [[Excel.CurrentWorkbook]] **Date** : 16-March-2025 # Description Looping in M-query is not as straight forward a with other scripting languages like python. In this tutorial I show you how to iterate and transform columns in a table without repeating the transformation manually. # Video Link <iframe width="560" height="315" src="https://www.youtube.com/embed/XV0JrQodY18?si=LqSFc5QYbdWIz2Ub" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" referrerpolicy="strict-origin-when-cross-origin" allowfullscreen></iframe> [GITHUB File Link](https://github.com/jbotes/powerbiTutorials/blob/main/PQ_Listaccumulate_video.xlsx) # M-Query ```mquery let Source = Excel.CurrentWorkbook(){[Name="Table1"]}[Content], ChangedType = Table.TransformColumnTypes(Source,{{"Stock Code", type text}, {"Portfolio1", Int64.Type}, {"Portfolio2", Int64.Type}, {"Portfolio3", Int64.Type}, {"Portfolio4", Int64.Type}, {"Portfolio 5", Int64.Type}, {"Portfolio 6", Int64.Type}, {"Portfolio 7", Int64.Type}}), TransformFunction = Table.TransformColumns(ChangedType, {{"Portfolio1", each _ / List.Sum(ChangedType[Portfolio1])}}), SelectedColumns = List.Select(Table.ColumnNames(ChangedType), each Text.Contains(_, "Portfolio", Comparer.OrdinalIgnoreCase)), Custom1 = List.Accumulate(SelectedColumns, ChangedType, (StateTableColumns, CurrentColumn)=> Table.TransformColumns(StateTableColumns, {{CurrentColumn, each _ / List.Sum(Table.Column(ChangedType,CurrentColumn ) )}})) in Custom1 ``` ## Optional Tags **Tags** : **Technique** : [[Looping]]