Regex expression in automation needs some tweaking

Configuration
,
1

Hi there,

I have an automation that I’m working on. It involves needing a regex expression to be able to filter calendar events. The logic should be as follows:

  1. If event begins with the letter T, return false. End.
  2. If there are 3 or 4 consecutive digits, return True.

Some examples:
“T7575” = False (begins with T)
“ABC 867 ZXY” = True (867)
“Pickup” = False
“Some words (55:76)” = False (only 2 consecutive numbers)
“YGF AB658 YHJ” = True (658)
“YGF 6658 YHJ” = True (6658)

Basically, as long as the event doesn’t begin with T and there are 3 or 4 numbers in a row anywhere, it should be true.

Other notes:

  • Sometimes there will be letters next to the numbers, sometimes not
  • Will have to be able to work with spaces before/after the letters (and ignore them). Sometimes spaces will be there, sometimes not.

Here is what I have so far:

value_template: >-
      {{ trigger.calendar_event.summary |
      regex_match('^(?!T).*\\b\\d{3,4}\\b.*') }}

So far, entries such as “ABC 123 XYZ” have been returning true, as it should. However it appears to fail when there are letters immediately next to the numbers. For example: “ABC DE875 XZY” should return true, but it’s returning false right now.

Any help would be greatly appreciated! Thanks in advance.

2

You’re leading word boundary is killing it. Using your example:

ABC DE875 XZY

\d{3,4} matches 875, but because there’s an E before 8 then your word boundary isn’t matching.

Not knowing all your use-cases, I’m guessing you want something more like

^(?!T).*\\d{3,4}.*

So it’ll return true as long as there’s a string of 3 or 4 numbers. Not sure the word boundaries are even necessary

image

Handy regex tool:

1 Like
3

I ran this in regex 101 and it returns positive on your string.

^[A-S,U-Z,a-z,0-9].*\d{3,4}.*
1 Like
4

That did the trick! Thank-you very much for the correction and additional information. Much appreciated!

5

Thank-you very much as well! Good to have options as I learn yaml and regex. Appreciate your time.