Does Alteryx has a simple Regex_search to return first matched substring in formula tool?

[luk]

I'm trying to extract sub-string from a main string,  e.g.  extract "c1234" from "abc1234efg".  In the past I can use a simple pattern "c\d*" to get what I need, but in Alteryx formula it seems doesn't have any way to do this.  The closest way is use REGEX_Replace,  but I have to change pattern to ".*(c\d*).*" plus use a mysterious "$1" in the end,  which is much more complicate and counter-intuitive.

I know there is a tool called "RegEx", but it does not support concatenate pattern string according to previous fields.

Does anyone have any idea about how to fulfill this function?  Thank you.

[Qiu]

@luk 

You still can I think

[luk]

Thank you, I know this tool, but what I want to do is concatenate pattern string like this:

The "key" is one of input field of formula tool.  Can RegEx tool also do this without creating macro?

[Qiu]

@luk 

Sorry about the misunderstanding.
But maybe your approach is the best I can think of/😁

[danilang]

Hi @luk 

Your example does exactly what you're looking for.

REGEX_Replace([Field1], ".*("+[Key]+"\d*).*", "$1")

Here are the results with some sample data

As @Qiu said, there's no way to get the Regex tool to be dynamic without a macro.  But why would you want to, when you have the solution using the formula tool?

Dan

Dan

[luk]

Thanks for reply,  I have this trouble because I wrote regex in both python and Alteryx,  and the pattern syntax is very different between them.  In this example,  it's "c\d*" in Python but ".*(c\d*).*" in Alteryx,  while the function is the same.

[BretCarr]

@luk I wanted to address the “mysterious $1” comment.

$1 is used to refer to the capture group in your expression. If you had more groups, they would increment $2, $3, etc.

This allows you to use your capture group and do something else with it once extracted. For example, you could do something like:

regex_replace(.........., ‘Ref#: ‘ +’$1’) to get a result of “Ref# C1234” if you were so inclined.

Hope that makes sense!

[luk]

Thank you,  I think this is the most tricky part.  If I use pattern "c.*f" for string "abcdefghi",  "$1" match nothing,  while in other language, it will match "cdef".  so if I copy the pattern from other language or devtool,  I have to rewrite it to Alteryx format.

[BretCarr]

If you do

(c.*f)

then it should work. The parentheses identifies the capture group. Without the parentheses, $1 isn’t going to have anything “captured” from a match.

Not sure if we are talking about the same thing but your pattern def works. 

[luk]

Sorry but 

(c.*f)

does not work on  2020.3.5, it must be like

.*(c.*f).*

I'm sure we are talking the same thing.