each & underscore_ in Power Query Explained

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Finally, the most requested video is here. I'll discuss the nuances of 'each' & '_' keywords in Power Query.
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===== CHAPTERS =====
0:00 Intro
0:16 Understanding 'each' & Underscore_ in a Context of a Table
2:45 Understanding 'each' & Underscore_ in a Context of a List
4:27 Alternate to 'each' & Underscore_ in a Table
7:05 Alternate to 'each' & Underscore_ in a List
8:48 My Courses
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[@amitk1208]

The best part of your teaching is you deep dive and great explanation and make the things easier to understand

[@GoodlyChandeep]

Thank you!

[@konigkakfas3392]

Short into the point - cool, thx!

[@navisalomi]

Thanks so much. It's good to know both the each syntax sugar and the declaring a variable like (r)=>. There are cases where you're nesting functions. Once you use each _ once, if you use it again , it overwrites the first one. So, be careful. If you must use each again, declare the variable. Example, Table.AddColumn(Source, "NewCol", each {_[Amount]} & List.Transform({2,3,4}, (x)=> x * _)). You can't use the each _ in the List.Transform function. You will overwrite the first _ and cause the functions to crash.

[@MichaelBrown-lw9kz]

This is by far the best explanation I have seen regarding "each" and "_". I finally understand this. Thank you so much

[@EmpyrialArchangel]

THANK YOU! I spent HOURS reading documentation, but all I needed was 10 minutes on KZbin. You're my hero!

[@Hello-bn2yc]

Finally I was able to get it... Thank you so much Chandeep.

[@mohamedfouad7958]

Love you man, I learned a lot from you and still learning

[@iantotheh]

Such an eloquent explanation of something I've been wondering for a while!

[@GoodlyChandeep]

Glad it was helpful !

[@ajieapen]

ah... I've been waiting for this since ages... No words to thank you, Chandeep... :)

[@rohanbhattacharyya6600]

Very informative. Thanks!

[@josecarlosconejo5724]

You are really good at explaining things… 👍

[@kamleshmistry2728]

hats off. thanks for great content.

[@rpopecpa]

Thank you for this video!! A simple bit of valuable information to add to my knowledge base.

[@seanys]

I wish I had seen this video when I first started trying to use Power Query.

[@mohitoshbiswas4797]

Great explanation of each and _ keywords and their applications. Thanks Chandeep 👍

[@QuantumIdeas]

Fantastic video, Chandeep! Each, _, () and => have been so mysterious to me before viewing this video. This is a huge for me.

[@isidreb]

A great explanation, using examples that are easy to understand. Thanks for sharing!!

[@GoodlyChandeep]

Glad you enjoyed it!

[@90hsilva]

very clear as usual mate, thanks :)

[@williamarthur4801]

Thank you, its' about time soneone tackled this topic, I rememeber when I first started looking at M being very cofused by the Fuction (_, , that I would see. I still find there use confusing / interesting in that sometimes using a named function eg (A)=> A[whatever], will work whereas each [whatever] , might not. Thank you for all your work in putting these videos together.

[@komanguy]

Great! Very well explained, the meaning of the underscore and how to define a function. Thank you very much.

[@GoodlyChandeep]

Glad you liked it

[@karimallahwala7022]

You teach great Knowledge. Very helpful thank so much.

[@GoodlyChandeep]

Glad it was helpful!

[@stephanedelaval6525]

Clear and neat. Thank you for the explanation

[@GoodlyChandeep]

Glad you like it !

[@EricHartwigConsulting]

Great video and really detailed explanation in the use of the "each" and "_". Thank you for making this video!

[@GoodlyChandeep]

Glad you like it!

[@skimpylemon8034]

Fantastic video with a excellent explanation! Thank you Chandeep!

[@GoodlyChandeep]

Glad you like it!

[@larmondoflairallen4705]

My prayers have been answered. Thank you, Chandeep!!!!

[@GoodlyChandeep]

You are welcome!

[@ramkumarsai9846]

Hi. I loved your way of explaining and I have learned lot of stuff from your video’s. I have strucked some part of the work like dynamically comes column headers from the row data. In power BI. Could you please help me on the same.

[@OdelLeal]

Great job and very helpful your information. Súper.

[@GoodlyChandeep]

Glad it was helpful!

[@pmsocho]

Great explanateion! Thanks!

[@GoodlyChandeep]

Glad you enjoyed it!

[@roywilson9580]

Thanks for the interesting video. I wish someone had explained this so clearly when I first tried to work out what the each and _ were doing and how to use them.

[@GoodlyChandeep]

Glad it was helpful!

[@johnfunet]

Very interesting video, thanks for the excellent way you explain step by step. Very professional.

[@GoodlyChandeep]

Glad you like it!

[@vacilando86]

Finally, It's understood 😄 , Thanks for your endless effort.

[@GoodlyChandeep]

Welcome!

[@ajayv304]

I watched this video a few months back and I listened to it now. Understood clearly. Thanks a lot.

[@GoodlyChandeep]

Glad it helped Ajay!

[@seamushand8439]

Thank you Chandeep, very well explained

[@GoodlyChandeep]

You're most welcome

[@user-bh2lg4xw5n]

Great!

[@dilip1able]

Awesome Chandeep

[@jaymehta3320]

Thanks for sharing this. Haven't used each and _ that much but this helps to encourage and see where I can use it to make the queries more efficient/effective.

[@GoodlyChandeep]

You are so welcome!

[@briandelaney6354]

Thanks for this explanation - very clearly explained 👊

[@GoodlyChandeep]

Glad you like it!

[@arunkumarkesavan6077]

Now I cant say to anyone that I am good in Power BI after watching your vidoes!!! you're the person to say it...

[@matheusosa]

Great explanation!

[@GoodlyChandeep]

Thanks!

[@OmisileKehindeOlugbenga]

Thank you Chandeep. Very simple to follow and remember.

[@GoodlyChandeep]

Glad you liked it!

[@wayneedmondson1065]

Awesome explanation Chandeep! I think of each as shorthand for the function (myVar)=> and underscore as the variable myVar, as in (using your example): (myVar)=> myVar[Amount] to extract the amount from the record. I believe it is confusing to people because they experience each and _ before learning to formally declare functions. If they learned the formal way first and then learned the shorthand of each and _ it might be easier. Thanks for a great explanation.. alway good learning at Goodly! Thumbs up!!

[@GoodlyChandeep]

I am with you a 💯 percent. That is also because the UI generates the shorthand code and that is what people see and try to understand.😁 Personally I feel the each _ is more humanly to read.

[@KuldeepSingh-nq1vi]

Most awaited Video, Thank you so much that you created video on this topic and very nicely explained each and "_" keyword. It will help us to understand complicated M code..I appreciate your dedication towards teaching us..we would expect other basic videos like this from you.. Please make video on how to create custom functions in power query from scratch..

[@GoodlyChandeep]

Most welcome 😊

[@IvanCortinas_ES]

Superb explanation. It can't be explained better. Thank you Chandeep!!!

[@GoodlyChandeep]

Glad you liked it!

[@matheussvs]

Thanks man! Youre amazing

[@GoodlyChandeep]

Glad you like it !

[@brij26579]

Awesome explanation & clarity 👌👍

[@GoodlyChandeep]

Glad you like it!

[@Bic2705]

I have a lot of difficulty creating a conditional transformation that involves more than one column. I would really like a video about it.

[@anilyadav-rt4sr]

Thanks Your power query video is too good

[@GoodlyChandeep]

Glad you enjoyed it!

[@kiran521]

Thanks Chandeep, please make video on problems occur in bidirectional direction and why it is not feasible

[@balakrishnaj1713]

This video is very helpful, thanks a ton 😀

[@GoodlyChandeep]

Glad it was helpful!

[@Faisal63045]

Thank you for sharing this info if there's any example from the real world scenario it would be great

[@GoodlyChandeep]

You are very welcome!

[@justinwduff]

I know very little about M, but how you explained this made a lot of sense. Thank you.

[@GoodlyChandeep]

Thanks Justin :) To learn more about M, You can refer to this video. kzbin.info/www/bejne/a6SbfKxrp5lmq6s

[@cooolbreeze]

Really well explained.

[@GoodlyChandeep]

Thank You !

[@elikent78]

spent an hour trying to understand this from someone else's lesson yesterday, and couldn't get it. but you, in ten minutes, done. fantastic, chandeep.

[@GoodlyChandeep]

Hey Eli, I spent an hour in planning the video to explain in 10 mins 😁 I am glad it helped. Cheers

[@FRANKWHITE1996]

Thanks for sharing ❤

[@GoodlyChandeep]

Thanks for watching!

[@kennethstephani692]

Great Video as usual, Chandeep!!

[@GoodlyChandeep]

Thank you!

[@avecNava]

each seconds of this video is great :)

[@GoodlyChandeep]

Glad you think so Nava!

[@stefaanlouette]

Awesome video

[@GoodlyChandeep]

Glad you enjoyed it

[@zahoorsarbandi2982]

The explanation of "each" and "_" has been been done in a very simple and effective way... zabar10

[@GoodlyChandeep]

Glad you like it!

[@stefanoconti4472]

Thank you very much, excellent and very clear explanation. Your videos are very beautiful and really helpful for everyone. But please try to speak SLOWER, your spoken English is too fast, sometimes the words overlap and it is not clear what you mean. Thank you

[@thebhaskarjoshi]

amazing thanks!

[@GoodlyChandeep]

Glad you like it!

[@bhaveshh5786]

Hey Chandeep, i want to calculate turn around time if a transaction received after 3pm it should consider next day to calculate it with close date. Also it should only consider the business days excluding Saturday and Sunday. Thanks in advance.

[@kerryhaxton1980]

Thanks for you time to help us along. I have an each and underscore that I'm trying to resolve. and maybe getting myself twisted up: I'm working on a sheet, and I want to change every occurrence of a character (% in my case) to a VALUE (Happens to be the Column header). I have the column names to which I'm applying the transformation in a list (Collist), and think I want to apply a process like List.Transform(Collist, each {_, each Text.Replace(_,"%", XXX)})) But I want the XXX to be represented by the same value from Collist. In my test sample Collist contains 3 values: When I change XXX to a literal, the process works, and all the "%" values are changed to "XXX".....but in real like I have a number of nested tables, with varying number/names of columns over which I need to perform the transformation: Sorry long winded question

[@user-ji5uk8tq8u]

Hi, thanks for the great explanation. A little crazy question... Is there any way to turn PQ editor in black theme as you did?

[@xaft]

Love your content and short explanations. Pls let me know if u have got discount for ur courses!!

[@oscarmendez-roca9181]

Great video and explanation with simple examples. I suggest to continue with the use of double "each" in case of working with arrays (List of a List). Thanks Chandeep!!

[@Vandalfoe]

Yes, please. I'm struggling to know how to work with 'each' row of a table, say, if one is added from a merge, for example. How do I access the "outside" underscore?

[@MrDonkey912]

@@Vandalfoe If you name your variables, you can access both, ex: = Table.AddColumn( s, "n", (row) => List.Select( l, each _ = row[Name] ), type any )

[@mohitupadhayay1439]

Chandeep praji Real time DAX scenario ki playlist bana dijye for interview.

[@alvarorodriguezlasso]

You are a crack, regards from Cali Colombia

[@GoodlyChandeep]

Thanks Alvaro!

[@muralidharannatarajan4251]

Super explanation

[@GoodlyChandeep]

Thanks!

[@gennarocimmino]

Thanks very much

[@GoodlyChandeep]

glad you like them!

[@kkhalidabed]

Well Done

[@GoodlyChandeep]

Thanks Khalid!

[@alexandresalome2684]

Excellent explanation, thank you! I have a question: is it possible to change the value of a simple item in a column, based (table.transformRows, each , if, then, else) on another column, without adding a new column? example: [Name] = a,b,c and [Years] = 10,20,30 if [Name ] = c then [Years] = 40 . (without using "table.addcollumns", that is, changing directly on column [Years]?) If yes, Is it possible create a video about it?

[@kebincui]

Well explained👍

[@GoodlyChandeep]

Thank you!

[@santoshpv321]

Supreme!!!

[@GoodlyChandeep]

Thanks!

[@Albert-zf8ct]

nice!

[@RobertoStaltari]

This video deserves a double thumb up!

[@GoodlyChandeep]

Thank you!

[@Moellz]

Hello Chandeep, great video. I really like the short explanations about one topic that you're posting recently. One question: Why does "r" in the section about alternate to each_ hold every record of the table? Is it because of the name?

[@GoodlyChandeep]

the variable name could be anything (r, x, abc, _) the variable holds the value of each item of the object (table, list etc..) and can be retrieved using a function => So all of the following are valid = Table.AddColumn(Table, "ColName", (abc) => abc) = Table.AddColumn(Table, "ColName", (_) => _) = Table.AddColumn(Table, "ColName", (myrecord) => myrecord)

[@mmuthuvel6829]

Very clear explanation. Do you have any course in Udemy?

[@yochintomimo5368]

👍

[@KirillBezzubkine]

I was wondering what "_" means. But actually i found more convenient to use " (x) =>" construction

[@Faisal63045]

Thank you for sharing this, is there a way to track values changes after refresh a power query in excel

[@GoodlyChandeep]

Not that I know of

[@oliverscheurich9202]

Great. You should have 320.000 subscribers instead of 32.000.

[@GoodlyChandeep]

Haha! Thanks

[@frachiar4444]

Grazie.😀

[@GoodlyChandeep]

Thank you so much 💖

[@sunnygala7972]

Great video! Do you cover all these concepts in your Power query course?

[@GoodlyChandeep]

working on an exclusive M Language course. Should be out soon :)

[@PawanKumar-nh3pi]

1:45

[@malchicken]

Very well explained thank you😊. When you declared (r) as a variable, could you have declared other variables that *don’t* represent the current record value? How complex can the functions used be? Does the variable always have to represent the current record? 🙏

[@GoodlyChandeep]

The variable name can be anything but you can only declare a single variable while you are working with records in a table.

[@Vandalfoe]

I believe that in the content of list.Xform and table.addColumn, that third parameter is being "fed" each (no pun intended) row/item of the first parameter. Therefore, whatever variable name you use, it will be loaded with 'each' item. @Goodly, is that about right?

[@MrDonkey912]

table: `_` is the record of the current row List: `_` is the current list item when looping Table.SelectRows: `_` is the record of the current row You can write your own functions, that validate better Here's two examples that assume your table has a column named "Number" which is a number = Table.AddColumn( Source, "Enforce Text", (row) as text => Text.From( row[Number] ) & " ending", type text) = Table.AddColumn( Source, "Enforce Int", (row) as number => row[Number] + 100, type number) the `as number` is a type assertion. Either the result is a number, else, that row throws an error. plus the columns datatype is correct! It doesn't reset to type any, because `each` is what caused it to lose the type

[@freedomdst]

can you put certain columns in a record and use it to show info on a regular tooltip? I wanted to show certain info depending on type of data, i had to concatenate columns based on conditions and even set titles for the data, like for data A "info1: " & "[info1)] & " " & "info2: "& [info2]... and so on.

[@vadnerepravin]

Question regarding power query I have many coulmn like Printing and Stationary 18%, repairing 18%, Consultancy 18% like that I want to Addition all this coulmn in Net 18% I have more than 200 ledger above said example. I have made table mentioned all ledger in left side like (consultancy 18%) and summation in coulmn right side like (Net18%) How can we dynamically addition above coulmn

[@LaloinLondon]

Thanks for sharing. Would you mind telling me how could you get amount without using the name 'Amount', just by position?

[@luigibru8677]

General question: any idea how to turn on in MacOs the syntax helper?

[@surjaa.c]

Thanks a lot for this video! My question is, are each and _ always used together like you have shown or can there be cases where only one of the two is used?

[@GoodlyChandeep]

the underscore can be used in isolation if you're writing a function. But if you've used the each keyword, it will always be followed by _

[@surjaa.c]

@@GoodlyChandeep thanks a lot! Please continue the 'good' work you are doing! 😁

[@Jonbooi]

Why can I use the _ as a shorthand for the column name in this formula if the _ holds the whole record? = Table.ReplaceValue(Source, each [Colum1], each if [Column1] = "AAA" then _ else "123" ,Replacer.ReplaceText,{"Column1"})

[@nishant77goel]

Help needed! Selected Parameter = maxx(filter('Date Value', 'Date Value'[Date Value Order] = SELECTEDVALUE('Date Value'[Date Value Order])), 'Date Value'[Date Value Fields]) This returns the name of selected column name based on the selected Parameter. Now based on the selected column name wants to calculate dates that falls in last 180 days on that partcular column. Last 180 days = IF([Selected Parameter] > (TODAY()-180),"1","0") This is giving error that the values/ Format are not matched one is date and other is text. As of now the dates column are in date time format.

[@GoodlyChandeep]

try wrapping the VALUE function around TODAY() VALUE ( TODAY () ) -180 ....

[@nishant77goel]

@@GoodlyChandeep this is not working. Value coming from selected parameter is not considered as column but is considered as text. So it's not matching up with today()-180 days condition. If I directly consider column the formula is working fine

[@gurjar5708]

moj ker de❤

[@GoodlyChandeep]

Thanks!

[@markhenderson3771]

Can I add ‘ and null to return a list of lists?

[@sandeepkhawas3367]

Can anyone suggest as getting this while using the same function in power query! Expression.Error: We cannot apply operator + to types Text and Number. Details: Operator=+ Left=1 Right=1

[@rajanpradeepankarath8846]

It would perhaps be better to understand the relevance if you had put in a practical life scenario on how to use this

[@gopalnaidu1103]

I have one unsolved query .could you please help me out .if the column contains the data as names and Gmail IDs and #twitter IDs ,and some other like diffent delimeters data .how to seperate the only names to one column and all Gmail IDs ,#twiiter IDs and delimeter data in to other column

[@saratoffice]

My table is inside a login page and the Login credential is known to me please reply on how to bring it to power query.

[@rashidkhan8161]

hi there, Could please help me to solve this, I have simple list Source = {a, b ,c , d}, when I use this List.Transform( Source, each [_=List.PositionOf(Source, _)]) it create list of record but every record showing filed name "_" , _=0, _=1 etc..

[@gennarocimmino]

try it this way let Source = {"a", "b", "c" , "d"}, Custom1 = List.Transform( Source, (r)=> List.PositionOf(Source, r) ) in Custom1

[@luigibru8677]

How Space is important in the syntax?

[@GoodlyChandeep]

Makes it look tidy. That's it