Clean up M code

[DonPepe]

Hello, 

I would like to know if you have another mean (more clean) to get the same result. And if not, how can I modify my code to be more understanble ? 

The purpose of the code is to filter the last week of the imported data (from sunday to saturday) 

let
    Source = Excel.Workbook(File.Contents("C:\Users\TabData.xlsx"), null, true),
    Tableau1_Table = Source{[Item="Tableau1",Kind="Table"]}[Data],
    AddDateMaxDb = Table.AddColumn(Table.TransformColumnTypes(Tableau1_Table,{{"PLAATY Start 
           Date", type date}}), "Personnalisé", each 
           List.Max(Table.TransformColumnTypes(Tableau1_Table,{{"PLAATY Start Date", type 
           date}})[PLAATY Start Date])),
    AddDateL = Table.AddColumn(AddDateMaxDb, "Personnalisé.1", each 
           Date.AddDays(Date.AddWeeks(Date.StartOfWeek([Personnalisé]),-1),-1)),
    #"Personnalisée ajoutée2" = Table.AddColumn(AddDateL, "Personnalisé.2", each if [PLAATY 
           Start Date] >= Date.AddDays(Date.AddWeeks(Date.StartOfWeek([Personnalisé]),-1),-1) 
           and [PLAATY Start Date] <= 
           Date.AddDays(Date.AddWeeks(Date.StartOfWeek([Personnalisé]),-1),+5) then [PLAATY 
           Start Date] else "O"),
    #"Colonnes supprimées" = Table.RemoveColumns(Table.SelectRows(#"Personnalisée ajoutée2", 
           each ([Personnalisé.2] <> "O")),{"Personnalisé", "Personnalisé.1", 
           "Personnalisé.2"})
in
    #"Colonnes supprimées"

Thanks in advance ! 

Don 

[wdx223_Daniel · Accepted solution]

let
    Source = Excel.Workbook(File.Contents("C:\Users\TabData.xlsx"), null, true),
    Tableau1_Table = Table.TransformColumnTypes(Source{[Item="Tableau1",Kind="Table"]}[Data],{{"PLAATY Start Date", type date}}),
    DateMax = List.Max(Tableau1_Table[PLAATY Start Date]),
    DateL = Date.AddDays(Date.AddWeeks(Date.StartOfWeek(DateMax),-1),-1),
    DateM = Date.AddDays(Date.AddWeeks(Date.StartOfWeek(DateMax),-1),+5),
    Custom1 = Table.SelectRows(Tableau1_Table,each [PLAATY Start Date] >=DateL and [PLAATY Start Date] <= DateM))
in
    Custom1

[DonPepe]

Wow, thanks a lot, I will learn from that. 

[BA_Pete]

Hi @DonPepe ,

Can you provide a copyable example of your source data please?

Make sure to remove any sensitive information before sharing.

Pete