Forum Discussion
Load multiple csv files, but different row counts until column heads
Hello,
I have multiple csv files that I want to load at once and combined with each other. These tables aren't typically formatted. I need to extract the date from the first second row as a additional column (to distinguish which csv I have) and afterwards delete empty rows and then put the columns into the head. There are sevaral empty rows until I reach the column line:
| Date | Timestamps | ||||||||||
| 01/01/2022 | |||||||||||
| Column A | Column B | Column C | Column D | Column E | Column F | ||||||
| xxx | xxx | xxx | xxx | xxx | xxx | ||||||
The problem I encounter now is that I have multiple csv files, where the column header sometimes has 4 rows that i need to delete to reach the top and sometimes more and less. Is there some command like delete only empty rows or until row =Column A?
Thank you very much in advance.
Best.
Hi Applicable88,
So, for your second issue, here's a function I use regularly to combine multiple CSV files where the number of unwanted rows varies.
// fProcessFiles let fProcessFiles = (myFile as binary) => let CSV = Csv.Document(myFile, [Encoding=1252]), ConditionalBlankIndex = Table.AddColumn(CSV, "Custom", each if [Column2] = "" then 0 else 1), HeaderPosition = List.PositionOf(ConditionalBlankIndex[Custom], 1), RemoveRows = Table.Skip(CSV, HeaderPosition), PromotedHeaders = Table.PromoteHeaders(RemoveRows, [PromoteAllScalars = true]) in PromotedHeaders in fProcessFilesChange the column reference '[Column2]' to a column that will be all blank until you hit a header.
Here's the other function I used in the main code.
// fNoHeader let fProcessFiles = (myFile as binary) => let CSV = Csv.Document(myFile, [Encoding=1252]) in CSV in fProcessFilesMain code:
let Source = Folder.Files("H:\My Drive\Power BI\Community Solutions\Files"), #"Filtered Rows" = Table.SelectRows(Source, each ([Name] = "headers_filereference.csv")), #"Removed Other Columns" = Table.SelectColumns(#"Filtered Rows", {"Content"}), #"Invoked Custom Function" = Table.AddColumn( #"Removed Other Columns", "Query1", each fProcessFiles([Content]) ), #"Invoked Custom Function1" = Table.AddColumn( #"Invoked Custom Function", "NoHeader", each fNoHeader([Content]) ), #"Added Custom" = Table.AddColumn( #"Invoked Custom Function1", "Custom", each [NoHeader]{1}[Column3] ), #"Removed Other Columns1" = Table.SelectColumns(#"Added Custom", {"Query1", "Custom"}), #"Expanded Query1" = Table.ExpandTableColumn( #"Removed Other Columns1", "Query1", { "Column A", "", "Column B", "_1", "Column C", "_2", "Column D", "_3", "Column E", "_4", "Column F", "_5" }, { "Column A", "Column1", "Column B", "_1", "Column C", "_2", "Column D", "_3", "Column E", "_4", "Column F", "_5" } ) in #"Expanded Query1"Basically...
- Connect to the folder with your files
- Remove all columns except your content
- Invoke both functions using the Add Column >> Invoke Custom Function
- Add a custom column referencing the detail you want to keep from each file
- Remove unwanted columns again
- Expand the column that has the table with filtered headers
Let me know if this requires further explanation.
3 Replies
- AlexisOlsonSuper User
The simplest approach would be to filter blanks from one of the columns but this requires that column to not have blanks in any rows you want to preserve.
- KNPSuper User
Hi Applicable88,
So, for your second issue, here's a function I use regularly to combine multiple CSV files where the number of unwanted rows varies.
// fProcessFiles let fProcessFiles = (myFile as binary) => let CSV = Csv.Document(myFile, [Encoding=1252]), ConditionalBlankIndex = Table.AddColumn(CSV, "Custom", each if [Column2] = "" then 0 else 1), HeaderPosition = List.PositionOf(ConditionalBlankIndex[Custom], 1), RemoveRows = Table.Skip(CSV, HeaderPosition), PromotedHeaders = Table.PromoteHeaders(RemoveRows, [PromoteAllScalars = true]) in PromotedHeaders in fProcessFilesChange the column reference '[Column2]' to a column that will be all blank until you hit a header.
Here's the other function I used in the main code.
// fNoHeader let fProcessFiles = (myFile as binary) => let CSV = Csv.Document(myFile, [Encoding=1252]) in CSV in fProcessFilesMain code:
let Source = Folder.Files("H:\My Drive\Power BI\Community Solutions\Files"), #"Filtered Rows" = Table.SelectRows(Source, each ([Name] = "headers_filereference.csv")), #"Removed Other Columns" = Table.SelectColumns(#"Filtered Rows", {"Content"}), #"Invoked Custom Function" = Table.AddColumn( #"Removed Other Columns", "Query1", each fProcessFiles([Content]) ), #"Invoked Custom Function1" = Table.AddColumn( #"Invoked Custom Function", "NoHeader", each fNoHeader([Content]) ), #"Added Custom" = Table.AddColumn( #"Invoked Custom Function1", "Custom", each [NoHeader]{1}[Column3] ), #"Removed Other Columns1" = Table.SelectColumns(#"Added Custom", {"Query1", "Custom"}), #"Expanded Query1" = Table.ExpandTableColumn( #"Removed Other Columns1", "Query1", { "Column A", "", "Column B", "_1", "Column C", "_2", "Column D", "_3", "Column E", "_4", "Column F", "_5" }, { "Column A", "Column1", "Column B", "_1", "Column C", "_2", "Column D", "_3", "Column E", "_4", "Column F", "_5" } ) in #"Expanded Query1"Basically...
- Connect to the folder with your files
- Remove all columns except your content
- Invoke both functions using the Add Column >> Invoke Custom Function
- Add a custom column referencing the detail you want to keep from each file
- Remove unwanted columns again
- Expand the column that has the table with filtered headers
Let me know if this requires further explanation.
- Applicable88Impactful Individual
KNP very appreciate the thorough answer. Thanks!