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"
"
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"\d: ([\w@]+): <(.+)> mtu (\d+) qdisc (\w+) qlen (\d+)\n[ ]+(\w+\/\w+) ([\d:\w.]+) brd ([\d:\w.]+)\n?(?:(?: )+inet6? ([\d.:\/]+) (?:brd ([\d:\w.]+) )?scope (\w+) (?:\w+)?\n(?: )+valid_lft (\w+) preferred_lft (\w+))?" test_str = ("1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue qlen 1\n" " link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00\n" " inet 127.0.0.1/8 scope host lo\n" " valid_lft forever preferred_lft forever\n" " inet6 ::1/128 scope host \n" " valid_lft forever preferred_lft forever\n" "2: lan1: <BROADCAST,MULTICAST,UP,LOWER_UP8000> mtu 1500 qdisc mq qlen 1000\n" " link/ether 00:60:e0:6a:48:26 brd ff:ff:ff:ff:ff:ff\n" " inet 10.32.39.55/24 brd 10.32.39.255 scope global lan1\n" " valid_lft forever preferred_lft forever\n" "3: lan2: <BROADCAST,MULTICAST,UP,LOWER_UP8000> mtu 1500 qdisc mq qlen 1000\n" " link/ether 00:60:e0:6a:48:27 brd ff:ff:ff:ff:ff:ff\n" " inet 192.168.90.1/20 brd 192.168.95.255 scope global lan2\n" " valid_lft forever preferred_lft forever\n" "4: sit0@NONE: <NOARP> mtu 1480 qdisc noop qlen 1\n" " link/sit 0.0.0.0 brd 0.0.0.0\n" "6: wwp0s29u1u3i12: <BROADCAST,MULTICAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000\n" " link/ether 00:00:11:12:13:14 brd ff:ff:ff:ff:ff:ff\n" " inet 172.16.224.124/16 brd 172.16.255.255 scope global wwp0s29u1u3i12\n" " valid_lft forever preferred_lft forever\n") 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