Regular Expressions 101

Save & Manage Regex

  • Current Version: 1
  • Save & Share
  • Community Library

Flavor

  • PCRE2 (PHP)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java
  • .NET 7.0 (C#)
  • Rust
  • PCRE (Legacy)
  • Regex Flavor Guide

Function

  • Match
  • Substitution
  • List
  • Unit Tests
Sponsors
An explanation of your regex will be automatically generated as you type.
Detailed match information will be displayed here automatically.
  • All Tokens
  • Common Tokens
  • General Tokens
  • Anchors
  • Meta Sequences
  • Quantifiers
  • Group Constructs
  • Character Classes
  • Flags/Modifiers
  • Substitution
  • A single character of: a, b or c
    [abc]
  • A character except: a, b or c
    [^abc]
  • A character in the range: a-z
    [a-z]
  • A character not in the range: a-z
    [^a-z]
  • A character in the range: a-z or A-Z
    [a-zA-Z]
  • Any single character
    .
  • Alternate - match either a or b
    a|b
  • Any whitespace character
    \s
  • Any non-whitespace character
    \S
  • Any digit
    \d
  • Any non-digit
    \D
  • Any word character
    \w
  • Any non-word character
    \W
  • Non-capturing group
    (?:...)
  • Capturing group
    (...)
  • Zero or one of a
    a?
  • Zero or more of a
    a*
  • One or more of a
    a+
  • Exactly 3 of a
    a{3}
  • 3 or more of a
    a{3,}
  • Between 3 and 6 of a
    a{3,6}
  • Start of string
    ^
  • End of string
    $
  • A word boundary
    \b
  • Non-word boundary
    \B

Regular Expression
Processing...

Test String

Code Generator

Language

Generated Code

import re regex = re.compile(r"(?:ALARM[\s]*)(?:\d*)[A-Za-z\s\d\.=]*(?:Alarm\sraised\stime)\s+=\s+([\d\-]+\s[\d\:]+)\s+(?:Location\sinfo)\s+=\s+Local\sCell\sID=([\d]+)(?:,\s[a-zA-Z]+\s[A-Z]+\s[A-Z]+\s[a-zA-Z\=,]+\s[a-zA-Z\=-]+\s[a-zA-Z\=-]+\s[a-zA-Z\=-_,]+)[\s\,A-Za-z0-9=\_]*(?:eNodeB\sID=)([0-9]+)(?:,.+\s\s+.+\s+)(?:Cleared\stype)\s+=\s+([a-zA-Z ]+)(?:[\sA-Za-z\s=]*)([\d-]*\s[\d:]+)", flags=re.MULTILINE) test_str = ("L_SAMBIL\n" "+++ L_SAMBIL 2020-09-21 11:53:53\n" "O&M #1502\n" "%%/*1882154167*/LST ALMLOG:ALMTP=all,CLRFLG=cleared-1&uncleared-1,CLRSD=2020&09&21,CLRED=2020&09&22,STARTAID=29240,ENDAID=29240;%%\n" "RETCODE = 0 Operation succeeded\n\n" "ALARM 72712 Fault Major eNodeB 29240 Signaling \n" " Sync serial No. = 162656\n" " Alarm name = Cell Unavailable\n" " Alarm raised time = 2020-09-21 06:36:19\n" " Location info = Local Cell ID=2, Cell FDD TDD indication=FDD, NB-IoT Cell Flag=FALSE, Cell Name=L_SAMBIL2, eNodeB ID=15080, Cell ID=2, Specific Problem=External link fault\n" " Function = eNodeB Function Name=L_SAMBIL, objId=0\n" " Cleared type = Normally cleared\n" " Cleared time = 2020-09-21 06:39:42\n" " Special info = RAT_INFO=L, AFFECTED_RAT=L, DID=NULL\n" " Special info1 = AF_L=L_SAMBIL\n\n" "ALARM 72713 Fault Major eNodeB 29240 Signaling \n" " Sync serial No. = 162655\n" " Alarm name = Cell Unavailable\n" " Alarm raised time = 2020-09-21 06:36:19\n" " Location info = Local Cell ID=3, Cell FDD TDD indication=FDD, NB-IoT Cell Flag=FALSE, Cell Name=L_SAMBIL3, eNodeB ID=15080, Cell ID=3, Specific Problem=External link fault\n" " Function = eNodeB Function Name=L_SAMBIL, objId=0\n" " Cleared type = Normally cleared\n" " Cleared time = 2020-09-21 06:39:41\n" " Special info = RAT_INFO=L, AFFECTED_RAT=L, DID=NULL\n" " Special info1 = AF_L=L_SAMBIL\n\n" "ALARM 72711 Fault Major eNodeB 29240 Signaling \n" " Sync serial No. = 162654\n" " Alarm name = Cell Unavailable\n" " Alarm raised time = 2020-09-21 06:36:19\n" " Location info = Local Cell ID=1, Cell FDD TDD indication=FDD, NB-IoT Cell Flag=FALSE, Cell Name=L_SAMBIL1, eNodeB ID=15080, Cell ID=1, Specific Problem=External link fault\n" " Function = eNodeB Function Name=L_SAMBIL, objId=0\n" " Cleared type = Normally cleared\n" " Cleared time = 2020-09-21 06:39:41\n" " Special info = RAT_INFO=L, AFFECTED_RAT=L, DID=NULL\n" " Special info1 = AF_L=L_SAMBIL\n" "(Number of results = 3)\n\n" "--- END") matches = regex.finditer(test_str) for match_num, match in enumerate(matches, start=1): print(f"Match {match_num} was found at {match.start()}-{match.end()}: {match.group()}") for group_num, group in enumerate(match.groups(), start=1): print(f"Group {group_num} found at {match.start(group_num)}-{match.end(group_num)}: {group}")

Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Python, please visit: https://docs.python.org/3/library/re.html