Regular Expressions 101

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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
No Match

r"
"
g

Test String

Code Generator

Language

Generated Code

# coding=utf8 # the above tag defines encoding for this document and is for Python 2.x compatibility import re regex = r"(?<=\s|\A)([^\s=]+)=(.*?)(?=(?:\s[^\s=]+=|$))" test_str = "eventId=588622 app=HTTP in=5326 out=5326 categorySignificance=/Normal categoryBehavior=/Communicate/Query categoryDeviceGroup=/Application catdt=Web Cache categoryOutcome=/Success categoryObject=/Host/Application/Service art=1359127995713 cat=Access Log deviceSeverity=2 rt=1359127975000 src=1.1.1.1 sourceZoneURI=/All Zones/ArcSight System/Public Address Space Zones/US Department of Defense dst=208.85.40.20 destinationZoneURI=/All Zones/ArcSight System/Public Address Space Zones/ARIN/204.0.0.0-209.255.255.255 (ARIN) dpt=80 fileType=application/json; request=http://www.pandora.com/json/music/artist/justin-moore?explicit\\=false requestMethod=GET requestClientApplication=Mozilla/5.0 (Windows NT 6.1) AppleWebKit/535.19 (KHTML, like Gecko) Chrome/18.0.1025.142 Safari/535.19 cs2=false cs3=http://www.pandora.com/ cs5=Default cs1Label=Virus Name cs2Label=AV Enabled cs3Label=Referrer cs4Label=URL Category cs5Label=Policy cs6Label=Reputation ahost=ndeusemslvarc04.gold.rtgold.nima.mil agt=214.28.240.186 agentZoneURI=/All Zones/ArcSight System/Public Address Space Zones/US Department of Defense av=5.2.7.6474.0 atz=GMT aid=3DLoiRDsBABCAA9FvE1htRg\\=\\= at=syslog dvchost=xxx-xxx-xxx dtz=GMT _cefVer=0.1 ad.charset=utf-8" matches = re.finditer(regex, test_str) for matchNum, match in enumerate(matches, start=1): print ("Match {matchNum} was found at {start}-{end}: {match}".format(matchNum = matchNum, start = match.start(), end = match.end(), match = match.group())) for groupNum in range(0, len(match.groups())): groupNum = groupNum + 1 print ("Group {groupNum} found at {start}-{end}: {group}".format(groupNum = groupNum, start = match.start(groupNum), end = match.end(groupNum), group = match.group(groupNum))) # Note: for Python 2.7 compatibility, use ur"" to prefix the regex and u"" to prefix the test string and substitution.

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