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"\[\@if(not)?:([a-zA-Z0-9]+)(?:=(.*?))?\].*?\[\@endif:\2\]", flags=re.DOTALL) test_str = ("<!-- <h1>[!WLANSettings]</h1> -->\n" "[@if:examplevar=notgiven]this text won't show[@endif:examplevar]\n" "[@if:wlanena]\n" "[@if:wlanauto]\n" "<table id=\"wlanavail\" class=\"colorrows inputtable\">\n" " <tr id=\"firstrow\">\n" " <th width=\"30px\"></th>\n" " <th width=\"240px\">[!Name] (SSID)</th>\n" " <th width=\"110px\">[!Encryption]</th>\n" " <th width=\"150px\">[!SignalStrength]</th>\n" " <th width=\"200px\">[!MAC]</th>\n" " </tr>\n\n" " <tr id=\"loadingrow\">\n" " <td colspan=5 class=\"centertext\"><img src=\"resources/loading.gif\"\n" " id=\"loadingWlanScan\"></td>\n" " </tr>\n" " <tr>\n" " <td></td>\n" " <td colspan=4><input type=\"button\" id=\"rescan\"\n" " value=\"[!Refresh]\" style=\"width: 200px\"></td>\n" " </tr>\n" "</table>\n" "<p></p>\n" "[@endif:wlanauto]\n" "<table id=\"wlansettings\" class=\"inputTable\">\n" " <tr id=\"wlannamerow\" [@if:wlanauto]style=\"display: none;\"[@endif:wlanauto]>\n" " <td>[!WLANName]</td>\n" " <td><input type=\"text\" name=\"wlanname\" id=\"wlanname\"\n" " [@if:wlanauto]value=\"[@wlanname]\"[@endif:wlanauto] style=\"width: 309px;\"></td>\n" " </tr>\n" " <tr>\n" " <td>[!Password]:</td>\n" " <td><input type=\"text\" name=\"wlanpass\" id=\"wlanpass\"\n" " style=\"width: 309px;\"></td>\n" " </tr>\n" " <tr>\n" " <td colspan=\"2\" >\n" " <input type=\"button\" \n" " [@if:wlanauto]id=\"manualcfg\" name=\"manualcfg\" value=\"[!ManualConfig]\"[@endif:wlanauto]\n" " [@ifnot:wlanauto]id=\"autocfg\" name=\"autocfg\" value=\"[!AutomaticConfig]\"[@endif:wlanauto]\n" " onclick=\"handleMultiform(event, this);\" style=\"width: 180px;\">\n" " </td>\n" " </tr>\n" " <tr>\n" " <td>\n" " <input type=\"hidden\" name=\"encinput\" id=\"encinput\" value=\"\"></td>\n" " <td id=\"wlaninfo\"></td>\n" " </tr>\n" "</table>\n" "[@ipsettings]\n\n" "[@endif:wlanena]\n" "[@ifnot:wlanena]\n" "[!NoWLANDevicePluggedIn]\n" "<p>\n" " <input type=\"button\" name=\"back\" onclick=\"handleMultiform(event, this);\" value=\"[!Back]\" />\n" "</p>\n" "[@endif:wlanena]\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