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(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})\s\d+?\s\d+?\s" test_str = ("# Bluecoat UPSTREAM Logs\n\n" "2016-08-31 00:02:54 18 172.25.21.173 - - - OBSERVED \"Non-Viewable/Infrastructure\" - 200 TCP_HIT GET application/ocsp-response http sr.symcd.com 80 /MFYwVKADAgEAME0wSzBJMAkGBSsOAwIaBQAEFHQkFGcGn%2FXgmD9ePhproGUqVBV1BBQBWavn3ToLWaZkY9bPIAdX1ZHnagIQUufCRVii4D52%2B1NnK%2BL%2Fmg%3D%3D - - \"ocspd/1.0.3\" 10.222.157.10 1957 316 -\n\n" "2016-08-31 00:02:54 18 172.25.19.32 - - policy_denied DENIED \"Chat (IM)/SMS;Content Servers\" http://im.qq.com/mobileqq 403 TCP_DENIED GET - http 203.205.144.22 80 /gchatpic_new/99787480/2125162524-3194779440-DD292643C193D85264F13026ED37A996/198 ?vuin=15929133&term=3&pictype=1003&cldver=6.5.0.443&rf=aio&msgTime=1472601651 - \"QQ/6.5.0.443 CFNetwork/758.3.15 Darwin/15.4.0\" 10.222.157.10 1185 421 -\n\n" "2016-08-31 00:02:54 199 172.25.26.70 - - - OBSERVED \"Technology/Internet\" - 200 TCP_NC_MISS POST application/json;charset=utf-8 http d.applovin.com 80 /device ?device_token=MaznYs97JTiqaqEwnZGZ5u0SoeBtsuRonBn0BJmm3q8hGZZkZ8TWjSHReUJMpRCoo6knaop8PaTY2Hg-vnNcBg34k9zTsGFYDOM6zvxdBDIykMF76uM-xuc_Km4oV6e5uf6-S_X6wDyE1kpriXzu5FBhmSNn4-E-PXKNuJvyqQM= - \"Dalvik/1.6.0 (Linux; U; Android 4.4.2; HTC One_E8 Build/KOT49H)\" 10.222.157.10 791 1227 -") 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