Welcome to the Alteryx Knowledge Base

How to Trim Numbers: Regex to the Rescue
user

Created/Edited - 4/27/2026 by Henriette Haigh | Alteryx

Procedure

Let's say you have data like this and you'd like to remove the numbers at the end:

Blue4509

Yellow2345

Orange2315

Blue6754

 

You could useLeft(x, len), like this:left([Data], (length([Data]) - 4))

(This calculates the length of the field, subtracts 4 and then takes that many characters from the left. E.g.: length(Blue4509) = 8, 8-4 = 4, left(Blue4509,4) = Blue)

 

Ora combination ofReverseString(Str) andSubstring(x, start, length):ReverseString(substring(ReverseString([Data]),4,100))

(This reverses the string, uses a substring to start at the 5th position [positions are zero based], takes the next 100 characters, and then reverses it back. E.g.: reversestring(Blue4509) = 9054eulB, 5th position = e, next 100 characters = eulB, reversing it back results in Blue)

BUT what if your data looks like this:

Blue4509
Yellow2345
Orange231
Blue6754
Green596828

 

The above won't work anymore, but ReplaceChar(x, y, z) will:replacechar([Data], '0123456789','')

(ReplaceChar(x,y,z)returns the string [x] after replacing each occurrence of the character [y] with the character [z].)

 

OrRegex_Replace(string, pattern, replace,icase):regex_replace([Data],"\d","")

(Regex_Replace(string, pattern, replace,icase) returns the string after replacing the pattern with the replace. In this case, it replaces all digits.)

 

Or the Regex Tool:

 

regx1.PNG

\d in regular expression identifies digits (aka numbers)

 

What if your data looks like this:

1Blue4509
2Yellow2345
3Orange231
4Blue6754
5Green596828

 

and you want to preserve the number at the beginning of the string but remove the ones at the end?

 

The $ character in regex denotes the end of the string, * identifies one or more instances of the preceding character,so \d*$ identifies one or more digits at the end of the string:regex_replace([Data], "\d*$","") or:

 

regx2.PNG

 

Also, check out all the other functions on the Alteryx help page,POSIX Extended Regular Expression Syntax, more info on the Regex Tool, and the Regex Cheat Sheet on the community.

 

 

Was this article helpful?