select values from list based on bolean array / list

[stevedep]

Hi,

I am trying to select values from a list where my bolean (true/false) list would indicate to select the column. 

Something like. 

List.Select(datalist, listwithtruefalsevalues)

Quite common in R and other languages, you select rows from you dataframe based on an array of true/false values. 

Hope its clear.

Kind regards, Steve. 

@edhans , @ImkeF 

[Zubair_Muhammad · Accepted solution]

@stevedep 

See if this help

let
    DataList= {1,2,3,4,5},
   Listwithtruefalse = {true,false,true,true,false},
Mergedlist=List.Zip({DataList,Listwithtruefalse }),

  Desiredlist = List.Transform(
List.Select(Mergedlist, (d)=>d{1}=true),(d)=>d{0})
in
    Desiredlist

[Zubair_Muhammad · Accepted solution]

@stevedep 

See if this help

let
    DataList= {1,2,3,4,5},
   Listwithtruefalse = {true,false,true,true,false},
Mergedlist=List.Zip({DataList,Listwithtruefalse }),

  Desiredlist = List.Transform(
List.Select(Mergedlist, (d)=>d{1}=true),(d)=>d{0})
in
    Desiredlist

[stevedep]

Thanks, I found a way to do it, turns out, it's the same approach as you suggest. So it probably makes sense 😃

[CNENFRNL · Accepted solution]

@stevedep @Zubair_Muhammad 

since you have 2 lists of the same lengths, why not use subscript to pick up responding values like this,

let
    DataList= {1,2,3,4,5},
    Listwithtruefalse = {true,false,true,true,false},
    Desiredlist = List.Accumulate({0..List.Count(Listwithtruefalse)-1}, {}, (s,c)=>if Listwithtruefalse{c} then s&{DataList{c}} else s)
in
    Desiredlist