Posts Tagged ‘Text transformation’

Trimming text with custom characters in Power BI and Power Query

When cleaning dirty data, you might have used the Trim-function (Text.TrimStart or Text.TrimEnd) to delete leading or trailing whitespace from your strings. However, did you know that you could use these functions as well to delete any other characters as well from the start or end of a string? Trimming text with custom characters is pretty straightforward:

Task: Trimming text with custom characters

Say you have a column with values like so

Trimming text with custom characters

and want to delete every number at the end and also every “-” that is directly connected with a number. So that the final output shall look like so:

Trim custom characters at the end of a string.

Optional parameter

By default, you feed just one argument into the Text.TrimStart or Text.TrimEnd function: The string whose whitespace characters shall be removed.

Text.TrimEnd(text as nullable text, optional trim as any) as nullable text

But the second argument lets you define a list of your own characters to be removed respectively. So I can create a list with all the characters that shall be removed from the end like so:

{"0".."9"} & {"-"}

This concatenates 2 lists: The first list contains 10 elements: All numbers as strings. The second list has just one element in it: “-“. I have to put this element into a list as well for being able to use the ampersand (“&”) as an easy concatenator here.

So the full expression for the “Add custom column” dialogue looks like so:

Text.TrimEnd( [MyColumnName], {"0".."9"} & {"-"} )

To see this in action, you can simply paste this code into the advanced editor and follow the steps:

Enjoy and stay queryious 😉

Improved Text.SplitAny – function for Power BI and Power Query

Today I’ll present an adjustment to the Text.SplitAny – function in Power BI’s query editor or Power Query. The native function takes a string as an input and splits the text by every character that is contained in the string. This seems fairly unusual to me and I haven’t used that function very often.

Problem

But what I have come across fairly often is the requirement to split a string by a bunch of different (whole) strings (instead of single characters).

Solution

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Return all occurrences of text between delimiters in Power BI and Power Query

The M-function Text.BetweenDelimiters does what it says and returns the text between 2 delimiters in the query editor of Power BI and Power Query. But irrespective of its optional arguments you can use to select specific occurrences, it will always only return one string found.

Problem

How to retrieve all occurrences of strings between in a text field like here for example: I’d like to get a list that contains “Python” and “R”:

“Meanwhile I prefer +Python!+ to +R!+”

Meaning all strings found between the delimiters “+” and “!+”.

Solution

This function will return the desired list:

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Transform text with exceptions in Power BI and Power Query

Recently I picked up an interesting request to transform text with exceptions: Transform the words in a column to proper case, but keep certain keywords like in a defined list.

Problem: Transform text with exeptions

Say you have a list with specific terms that shouldn’t be proper cased like so:

And you want to proper case the following column:

Convert to proper case with exceptions

So I proper case each word that is not contained in the “KeepTable”, identify the elements in the “KeepTable” in a case insensitive way and transform them into the syntax that’s specified in the “KeepTable”.

Solution

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