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cmengel's avatar
cmengel
Advocate II
5 years ago
Solved

Use Text.StartsWith and List.Contains to efficiently build custom columns

Hi!

 

Has anyone figured out the best way to use List.Contains in combo with Text.StartsWith in PowerQuery?

 

I create custom Y/N columns in PQ to make my DAX measures easier to write by filtering on these columns.

 

Recent example:

#"AddedEXPENSE" =
        Table.AddColumn(
            AddedALLOWED,
            "EXPENSE",
            each
                if
        //  Explicitly define EXPENSE codes
                    List.Contains(
                        {
                            "3L",
                            "3K",
                            "3O",
                            // letter "oh" NOT ZERO!!!
                            "3A",
                            "3E",
                            "3G",
                            "3B",
                            "3F",
                            "3M",
                            "3S",
                            "3J",
                            "3H"
                        },
                        [WO_LABOR_CLASS_CODE]
                    )
                then
                    "Y"
        //  Explicitly define NON-EXPENSE codes
                else if
                List.Contains(
                        {
                            "3C",
                            "3I",
                            "3V",
                            "3P",
                            "3Q",
                            "3N",
                            "3W",
                            "3X"
                        },
                        [WO_LABOR_CLASS_CODE]
                    )
                    or
                    Text.StartsWith(
                        [WO_LABOR_CLASS_CODE],
                        "A"
                    )
                    or
                    Text.StartsWith(
                        [WO_LABOR_CLASS_CODE],
                        "B"
                    )
                    or
                    Text.StartsWith(
                        [WO_LABOR_CLASS_CODE],
                        "C"
                    )
                    or
                    Text.StartsWith(
                        [WO_LABOR_CLASS_CODE],
                        "1"
                    )
                    or
                    Text.StartsWith(
                        [WO_LABOR_CLASS_CODE],
                        "2"
                    )
                then
                    "N"
                else if
                    [WO_LABOR_CLASS_CODE] = "NON_LABOR" then
                    "N"
        //  Catch items that are not explicitly defined or mapped
                else
                    "CLARIFY",
            type text
        ),
 
Notice how the first clause uses the List.Contains function.  I like this function a lot - easier to write, read, test, maintain, etc.
 
The second clause is more verbose and terribly inefficient to write, read, process, etc.
 
My objective is to write the second clause in such a way that I can use the Text.StartsWith function and provide a List.Contains function.  I think it'll speed up my query (and shorten it!).
 
I'm not a PQ / M code expert.  Any help suggestions is greatly appreciated.  Thanks in advance!
 
PS - I've taken to writing my PowerQuery stuff in Visual Studio Code and it is a GREAT way to work!  Highly recommend - especially for newbies like me!
 
Cheer!
Chris
Need Help
  • edhans's avatar
    edhans
    5 years ago

    You can just use this formula cmengel if I am reading your requirements correctly:

    List.Contains({"A", "S"}, Text.Start([Column1], 1))

    That returns a true or false if the text in column1 starts with an A or S, but not an R. So to make it part of your overall function:

    #"AddedEXPENSE" =
        Table.AddColumn(
            AddedALLOWED,
            "EXPENSE",
            each
                if
        //  Explicitly define EXPENSE codes
                    List.Contains(
                        {
                            "3L",
                            "3K",
                            "3O",
                            // letter "oh" NOT ZERO!!!
                            "3A",
                            "3E",
                            "3G",
                            "3B",
                            "3F",
                            "3M",
                            "3S",
                            "3J",
                            "3H"
                        },
                        [WO_LABOR_CLASS_CODE]
                    )
                then
                    "Y"
        //  Explicitly define NON-EXPENSE codes
                else if
                List.Contains(
                        {
                            "3C",
                            "3I",
                            "3V",
                            "3P",
                            "3Q",
                            "3N",
                            "3W",
                            "3X"
                        },
                        Text.Start([WO_LABOR_CLASS_CODE], 2)
					)
                then
                    "N"
                else if
                    [WO_LABOR_CLASS_CODE] = "NON_LABOR" then
                    "N"
        //  Catch items that are not explicitly defined or mapped
                else
                    "CLARIFY",
            type text
        ),

     

6 Replies

  • edhans's avatar
    edhans
    Community Champion
    5 years ago

    You can just use this formula cmengel if I am reading your requirements correctly:

    List.Contains({"A", "S"}, Text.Start([Column1], 1))

    That returns a true or false if the text in column1 starts with an A or S, but not an R. So to make it part of your overall function:

    #"AddedEXPENSE" =
        Table.AddColumn(
            AddedALLOWED,
            "EXPENSE",
            each
                if
        //  Explicitly define EXPENSE codes
                    List.Contains(
                        {
                            "3L",
                            "3K",
                            "3O",
                            // letter "oh" NOT ZERO!!!
                            "3A",
                            "3E",
                            "3G",
                            "3B",
                            "3F",
                            "3M",
                            "3S",
                            "3J",
                            "3H"
                        },
                        [WO_LABOR_CLASS_CODE]
                    )
                then
                    "Y"
        //  Explicitly define NON-EXPENSE codes
                else if
                List.Contains(
                        {
                            "3C",
                            "3I",
                            "3V",
                            "3P",
                            "3Q",
                            "3N",
                            "3W",
                            "3X"
                        },
                        Text.Start([WO_LABOR_CLASS_CODE], 2)
					)
                then
                    "N"
                else if
                    [WO_LABOR_CLASS_CODE] = "NON_LABOR" then
                    "N"
        //  Catch items that are not explicitly defined or mapped
                else
                    "CLARIFY",
            type text
        ),

     

    • Anonymous's avatar
      Anonymous
      Not applicable
      5 years ago

      That's pretty slick, Ed! 

    • cmengel's avatar
      cmengel
      Advocate II
      5 years ago

      Thank you edhans !  This worked perfectly!  Greatly appreciated.  Have an excellent day!

  • Anonymous's avatar
    Anonymous
    Not applicable
    5 years ago

    I would use this "else if" instead of the "or"s:

     

    else if List.Contains({"A", "B", "C", "1", "2"}, Text.ToList(Text.Start([WO_LABOR_CLASS_CODE], 1))) then "N" else if...

     

    --Nate

     

    If you

    • cmengel's avatar
      cmengel
      Advocate II
      5 years ago

      Hey, Anonymous !  Thanks for the reply.  I found the Text.ToList function unneccessary in this case.

      Appreciate you taking the time!