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

/
/
gmi

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"(?<type>.{1})(?<user_access>.{3})(?<group_access>.{3})(?<other_access>.{3}) +(?<oder>[0-9]*) +(?<owner>[a-z]*) +(?<group>[a-z]*) +(?<size>\d*) +(?<month>[a-z]{3}) +(?<day>\d{1,2}) +(?<year>\d{0,4})(?<time>(?<hour>\d{2}):(?<minute>\d{2}))? +(?<filename>(?<basename>.+)\.(?<extension>.*)|(?<no_extension_filename>.*))" test_str = ("total 80\n" "drwxr-xr-x 2 root root 4096 Sep 23 15:20 bin\n" "drwxr-xr-x 3 root root 4096 Sep 3 18:41 boot\n" "drwxr-xr-x 3 root root 4096 Aug 19 20:48 build\n" "drwxr-xr-x 14 root root 3900 Sep 23 15:20 dev\n" "drwxr-xr-x 98 root root 4096 Sep 23 15:20 etc\n" "drwxr-xr-x 4 root root 4096 Oct 6 2014 home\n" "drwxr-xr-x 21 root root 4096 Aug 21 19:49 lib\n" "drwxr-xr-x 2 root root 4096 Jul 8 13:21 lib64\n" "drwx------ 2 root root 16384 Aug 26 2014 lost+found\n" "drwxr-xr-x 2 root root 4096 Aug 26 2014 media\n" "drwxr-xr-x 2 root root 4096 Apr 10 2014 mnt\n" "drwxr-xr-x 2 root root 4096 Aug 26 2014 opt\n" "dr-xr-xr-x 133 root root 0 Sep 23 15:20 proc\n" "drwx------ 4 root root 4096 Sep 23 15:27 root\n" "drwxr-xr-x 22 root root 760 Sep 23 17:40 run\n" "drwxr-xr-x 2 root root 12288 Sep 23 15:20 sbin\n" "drwxr-xr-x 2 root root 4096 Aug 26 2014 srv\n" "dr-xr-xr-x 13 root root 0 Sep 23 15:20 sys\n" "drwxrwxrwt 2 root root 4096 Sep 23 17:40 tmp\n" "drwxr-xr-x 10 root root 4096 Aug 26 2014 usr\n" "drwxr-xr-x 14 root root 4096 Aug 21 19:52 var\n") matches = re.finditer(regex, test_str, re.MULTILINE | re.IGNORECASE) 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