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

/
/
gm

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"\b([0-9]{1,2})\.[0-9]{1,2}\.[0-9]{3,4}[\.]{0,1}[0-9]{0,4}" test_str = ("Microsoft SQL Server 2008 (SP1) - 10.0.2531.0 (X64) Mar 29 2009 10:11:52\n" "Copyright (c) 1988-2008 Microsoft Corporation \n" "Express Edition (64-bit) on Windows NT 6.1 <X64> (Build 7600: )\n\n\n" "↓SQL Server 2016 – 13.00.900.73 (CTP3.2)\n" "↓SQL Server 2014 12.00.2000.8 12.0.4100.1 12.0.4436.0 (SP1 CU4)\n" "↓SQL Server 2012 11.00.2100.60 11.00.3000 11.00.5058 11.00.6020 11.0.6020 (SP3)\n" "↓SQL Server 2008R2 10.50.1600.1 10.50.2500 10.50.4000 10.50.6000 10.50.6529 (MS15-058)\n" "↓SQL Server 2008 10.00.1600.22 10.00.2531 10.00.4000 10.00.5500 10.00.6000 10.00.6535 (MS15-058)\n" "↓SQL Server 2005 9.00.1399.06 9.00.2047 9.00.3042 9.00.4035 9.00.5000 9.00.5324 (MS12-070)\n" "↓SQL Server 2000 8.00.194 8.00.384 8.00.532 8.00.760 8.00.2039 8.00.2305 (MS12-060)\n" "↓SQL Server 7.0 7.0.623 7.0.699 7.0.842 7.00.961 7.00.1063 7.00.1152 (MS08-040)") matches = re.finditer(regex, test_str, re.MULTILINE) 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