Regex Filter to Eliminate Records with AlphaNumeric Before Letter "I"

Question

Need help narrowing the scope of this Regex to not return records if there is an alphanumeric character preceding the first "I"

"I([ ]{1,2})([a-zA-Z]|\d){2,13}"

Want to capture I APF From this string, but not the I ARPT.

I APF                     'NAPLES MUNI ARPT.            ' 42894 JEB 29785584

Thanks!

Answer 1

\b represents a word boundary in regular expressions, so the following should work (assuming you're happy with the rest of the regex):

("\bI([ ]{1,2})([a-zA-Z]|\d){2,13}")

A word boundary is defined as the zero-width space between a word character and a non-word character. Depending on your regex engine a word character is likely to be an alphanumeric character or an underscore, so using \b will match I ALF in -I ALF but not in _I ALF

Answer 2

\bI[ ]{1,2}[A-Za-z0-9]{2,13}

Answer 3

You could try doing a negative look-behind:

(?<![a-zA-Z0-9])I([ ]{1,2})([a-zA-Z]|\d){2,13}

I'm not sure how widely it will work though (i.e. using different regex libraries)

Answer 4

The word boundary seems like a good solution. You don't tell us what regex engine/language you will use: JavaScript doesn't have look-behind, for example.
And as the other pointed out, your expression is a bit too convoluted (which hurts speed).
My version would be:

\bI  ?[A-Za-z\d]{2,13}

With or without captures, depending on your needs. You might want to end the expression with \b too, to ensure there are no more alphanumeric characters after the expression.