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

/
/
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"([a-zA-Z]+\s+[\d:]+\s[\d:]+)\s(\S+)\s(\S+):\s([\d]+-[\d]+-[\d]+\s[\d]+:[\d]+:[\d]+)?\s?(.*)" test_str = ("Apr 15 10:34:05 scisp1 couriertcpd: Connection, ip=[::ffff:10.224.0.141]\n" "Apr 15 10:34:05 scisp1 couriertcpd: LOGIN: ip=[::ffff:10.224.0.141], command=LOGIN\n" "Apr 15 10:34:05 scisp1 couriertcpd: LOGIN: ip=[::ffff:10.224.0.141], username=61881227312\n" "Apr 15 10:34:05 scisp1 couriertcpd: LOGIN, user=61881227312, ip=[::ffff:10.224.0.141], port=[59372], protocol=IMAP\n" "Apr 15 10:34:51 scisp1 couriertcpd: TIMEOUT, user=61261886140, ip=[::ffff:10.224.0.141], headers=0, body=0, rcvd=747751, sent=43459, time=1835\n" "Apr 15 10:34:55 scisp1 couriertcpd: TIMEOUT, user=61881226690, ip=[::ffff:10.224.0.141], headers=0, body=0, rcvd=242597, sent=10564, time=1812\n" "Apr 15 10:34:55 scisp1 couriertcpd: LOGOUT, user=61881227312, ip=[::ffff:10.224.0.141], headers=0, body=438023, rcvd=1300, sent=447936, time=50\n" "Apr 15 10:35:04 scisp1 exim[24212]: 2016-04-15 10:35:04 no IP address found for host 103-55-116-16.sipcity.com.au (during SMTP connection from [103.55.116.16])\n" "Apr 15 10:35:04 scisp1 exim[24212]: 2016-04-15 10:35:04 1aqriy-0006IW-8u <= support@sipsolutions.com.au H=(scvm1.sipcity.com.au) [103.55.116.16] P=esmtps X=TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128 S=34149 id=Asterisk-4-132550271-61385471055-990@scvm1\n" "Apr 15 10:35:06 scisp1 exim[24213]: 2016-04-15 10:35:06 1aqriy-0006IW-8u => bp@grindalpatrick.com.au R=dnslookup T=remote_smtp H=filter1.grinda-1.mailguard.com.au [103.248.191.202] X=TLS1.0:RSA_AES_128_CBC_SHA1:128 C=\"250 2.0.0 Ok: queued as C2CB94261A3 UID 571037396f7ee5bc\"\n" "Apr 15 10:35:06 scisp1 exim[24213]: 2016-04-15 10:35:06 1aqriy-0006IW-8u Completed\n" "Apr 15 10:35:08 scisp1 exim[24231]: 2016-04-15 10:35:08 no IP address found for host 103-55-116-18.sipcity.com.au (during SMTP connection from [103.55.116.18])\n" "Apr 15 10:35:08 scisp1 exim[24231]: 2016-04-15 10:35:08 1aqrj2-0006Ip-7E <= customerservice@sipcity.com.au H=(scfax1.sipcity.com.au) [103.55.116.18] P=esmtps X=TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128 S=250689 id=20160415003508.GA29682@scfax1.sipcity.com.au\n" "Apr 15 10:35:10 scisp1 exim[24232]: 2016-04-15 10:35:10 1aqrj2-0006Ip-7E => admin@northernurology.com.au R=dnslookup T=remote_smtp H=remote.northernurology.com.au [58.108.247.139] X=TLS1.0:ECDHE_RSA_AES_256_CBC_SHA1:256 C=\"250 2.6.0 <20160415003508.GA29682@scfax1.sipcity.com.au> [InternalId=9647] Queued mail for delivery\"\n" "Apr 15 10:35:10 scisp1 exim[24232]: 2016-04-15 10:35:10 1aqrj2-0006Ip-7E -> darcy@northernurology.com.au R=dnslookup T=remote_smtp H=remote.northernurology.com.au [58.108.247.139] X=TLS1.0:ECDHE_RSA_AES_256_CBC_SHA1:256 C=\"250 2.6.0 <20160415003508.GA29682@scfax1.sipcity.com.au> [InternalId=9647] Queued mail for delivery\"\n" "Apr 15 10:35:13 scisp1 exim[24232]: 2016-04-15 10:35:13 1aqrj2-0006Ip-7E => suki01@gmail.com R=dnslookup T=remote_smtp H=gmail-smtp-in.l.google.com [74.125.68.26] X=TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128 C=\"250 2.0.0 OK 1460680513 fl6si10358337pad.46 - gsmtp\"\n" "Apr 15 10:35:14 scisp1 exim[24232]: 2016-04-15 10:35:14 1aqrj2-0006Ip-7E => admin@coralseaent.com.au R=dnslookup T=remote_smtp H=aspmx.l.google.com [74.125.68.27] X=TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128 C=\"250 2.0.0 OK 1460680514 vz3si1300160pab.93 - gsmtp\"\n" "Apr 15 10:35:14 scisp1 exim[24232]: 2016-04-15 10:35:14 1aqrj2-0006Ip-7E Completed") 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