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
Processing...

Test String

Code Generator

Language

Generated Code

import re regex = re.compile(r"^(\%.*|Command rejected.*)", flags=re.MULTILINE) test_str = ("**State Acronym: H - Healthy, W - Warning, C - Critical\n" "Resource Usage Max Warning Critical State\n" "----------------------------------------------------------------------------------------------------\n" "RP0 (ok, active) H\n" " Control Processor 29.42% 100% 80% 90% H\n" " DRAM 2840MB(72%) 3938MB 88% 93% H\n" " bootflash 1889MB(69%) 2753MB 70% 90% H\n" "ESP0(ok, active) H\n" " QFP H\n" " DRAM 81237KB(41%) 196608KB 85% 95% H\n" " IRAM 207KB(10%) 2048KB 85% 95% H\n" " CPU Utilization 2.00% 100% 90% 95% H\n\n" "Load Average\n" " Slot Status 1-Min 5-Min 15-Min\n" " RP0 Healthy 1.24 1.20 1.23\n\n" "Memory (kB)\n" " Slot Status Total Used (Pct) Free (Pct) Committed (Pct)\n" " RP0 Healthy 4033104 2909060 (72%) 1124044 (28%) 3749844 (93%)\n\n" "CPU Utilization\n" " Slot CPU User System Nice Idle IRQ SIRQ IOwait\n" " RP0 0 3.51 4.89 0.00 90.10 0.95 0.53 0.00\n" " 1 2.96 4.55 0.00 90.98 1.06 0.42 0.00\n" " 2 21.93 2.01 0.00 75.28 0.67 0.09 0.00\n" " 3 29.17 34.41 0.00 25.93 10.09 0.37 0.00\n\n\n\n\n\n" " 2222233333111111111111111111111111111111 111112222222222\n" " 100\n" " 90\n" " 80\n" " 70\n" " 60\n" " 50\n" " 40\n" " 30\n" " 20\n" " 10\n" " 0....5....1....1....2....2....3....3....4....4....5....5....6\n" " 0 5 0 5 0 5 0 5 0 5 0\n" " CPU% per second (last 60 seconds)\n\n\n\n\n" " 1 1 1 1 1 1 1\n" " 439546515464943339403403334255420343303354853430442395424873\n" " 100\n" " 90\n" " 80\n" " 70\n" " 60\n" " 50\n" " 40\n" " 30\n" " 20\n" " 10 ** **#* * # * * * *** * * * ** * ** *\n" " 0....5....1....1....2....2....3....3....4....4....5....5....6\n" " 0 5 0 5 0 5 0 5 0 5 0\n" " CPU% per minute (last 60 minutes)\n" " * = maximum CPU% # = average CPU%\n" "% Ambiguous command\n" "% Invalid input detected at '^' marker\n" "% Bad Mask /xx for address X.X.X.X\n" "% X.X.X.X overlaps with GigabitEthernet0/1\n" "Command rejected: Conflict between 'nonegotiate' and 'dynamic' status\n" "% Configuration of multiple subinterfaces of the same main interface with the same VID is not permitted\n" "% Configuring IP routing on a LAN subinterface is only allowed if that subinterface is already configured as part of a VLAN\n" "% Inconsistent address and mask\n" "% Invalid next hop address (it's this router)\n\n\n\n") matches = regex.finditer(test_str) for match_num, match in enumerate(matches, start=1): print(f"Match {match_num} was found at {match.start()}-{match.end()}: {match.group()}") for group_num, group in enumerate(match.groups(), start=1): print(f"Group {group_num} found at {match.start(group_num)}-{match.end(group_num)}: {group}")

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