regex101: Python Match Workspace

Explanation

Pro

(?i)applies the following effective flags to the remainder of the pattern: gi

i modifier: insensitive. Matches without distinguishing uppercase and lowercase letters

\s*a Unicode whitespace character, repeated any number of times

Group 1((?:Ext|Ex|X(?<!FAX))[- .]*\d{1,4}(?![-\d]))

Non-Capturing Group(?:Ext|Ex|X(?<!FAX))

1st AlternativeExt

Extthe literal text Ext (case insensitive)

2nd AlternativeEx

Exthe literal text Ex (case insensitive)

3rd AlternativeX(?<!FAX)

Xthe literal X (88₁₀ / 130₈ / 58₁₆) (case insensitive)

Negative Lookbehind(?<!FAX)

FAXthe literal text FAX (case insensitive)

Character Class[- .]*

*matches any number of characters from the set below:

-the literal - (45₁₀ / 55₈ / 2D₁₆)

the literal (32₁₀ / 40₈ / 20₁₆)

.the literal . (46₁₀ / 56₈ / 2E₁₆)

\d{1,4}a Unicode decimal digit, repeated between 1 and 4 times

Negative Lookahead(?![-\d])

Character Class[-\d]

-the literal - (45₁₀ / 55₈ / 2D₁₆)

\da Unicode decimal digit

Global pattern flags

g modifier: global. Finds all matches instead of stopping after the first

Quick Reference

25 tokens

Regular Expression

(?i)\s*((?:Ext|Ex|X(?<!FAX))[- .]*\d{1,4}(?![-\d]))

New

From the pattern I have right now i can match on numbers like Ext. 115, X 256, Ex 2114 only when no other numbers are present. However when a phone number is present I'll match that first or when a fax is indicated from the string "Jane Doe 888-888-8888/Fx 888-8888 ill match on x 888-8888. Input strings "Jane EXT. 115", "Jane X289 FAX 888-888-8888", "John Doe-X 241 OR CELL888/8888888" Output is "EXT. 115", "X289", "X 241" Other input I have is "Jane Doe 888-888-8888", "John Doe FX 888-888-8888" which matches on "e 888-888-8888", and "X 888-888-8888" when there is no extension present

Extraction

From the pattern I have right now i can match on numbers like Ext. 115, X 256, Ex 2114 only when no other numbers are present. However when a phone number is present I'll match that first or when a fax is indicated from the string "Jane Doe 888-888-8888/Fx 888-8888 ill match on x 888-8888. Input strings "Jane EXT. 115", "Jane X289 FAX 888-888-8888", "John Doe-X 241 OR CELL888/8888888" Output is "EXT. 115", "X289", "X 241" Other input I have is "Jane Doe 888-888-8888", "John Doe FX 888-888-8888" which matches on "e 888-888-8888", and "X 888-888-8888" when there is no extension present