Regular Expressions 101

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Function

  • Match
  • Substitution
  • List
  • Unit Tests (10)
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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"^(?=.*[A-Z])(?=.*[a-z])(?=.*[0-9])[\w!@#$%]{6,}$", flags=re.MULTILINE) test_str = ("INVALID:\n" "abcdefg\n" "abc\n" "abcdefghji\n" "abCDEFghij\n" "1234efghij\n" "abcde6789\n" "ab!67fghij\n" "ab)=\n\n" "VALID:\n" "8vB0k3XiLp\n" "VvsfM5he#X\n" "d10STfJ$gA\n" "R1cIX7mn8T\n" "6EDNTbda%z\n" "IKkED0#zYS\n" "1S#9duFcHe\n" "KP1fN3jTwJ\n" "iRS1YB@nfI\n" "Vp1yRxwuGD\n" "fajT2ukURg\n" "9tY8#HkojR\n" "@LHTbA3C7J\n" "%HLK6EqANV\n" "#vZR6in5KJ\n" "!WwjH3K65v\n" "%5WOIrCv@R\n" "emfpLRE5oD\n" "zREw13rcJn\n" "#NU42oxYa0\n" "$oujwK%xR7\n" "1YH#uOFQlV\n" "L936DS2ynR\n" "ab4RAVCZHv\n" "9xwiZmDSAd\n" "eZjPHg3B8i\n" "OANw!p8yxH\n" "J6efM@hxNz\n" "qvmefZI3Wn\n" "fH9wXGK8ZI\n" "eHcl3qRYGS\n" "i8we0zpOvr\n" "1kpSFgeIKA\n" "p8eM@FtZ9n\n" "rj95zq!E3I\n" "lkDKt@486w\n" "7!j50lyxgB\n" "%vBCxLq6Ym\n" "@ky$u9iSGm\n" "%QD9jA6Lm@\n" "JolTzf7gUr\n" "cSRe%v46Or\n" "oJVlc#Gdn3\n" "G!%NF0XESp\n" "76dMFmbf%X\n" "3JQlSRiXLj\n" "Y$!%WCgti0\n" "D1k$#ThiqG\n" "M6tPY$XzQp\n" "@gUcrWm7zA\n" "1xc#hwGj0D\n" "s8p#S$ZkWP\n" "sIP3dQL#4j\n" "bBLEnvlFI3\n" "isSeP4AC%w\n" "1OsdI4iCjR\n" "@p#qm$NA9Z\n" "guPjtIp5!i\n" "a84ONQRZXY\n" "homJ9T6w80\n" "$!uh09kaUO\n" "CTIX7vsalJ\n" "2CASR7IUyY\n" "Tr1jl!oKPF\n" "2%ar6kMCZe\n" "m4TrLJC!cD\n" "3E#mZ!jrdn\n" "oZIa$xmDU8\n" "9wXxBaJAyz\n" "0%dNQfyr$e\n" "ez#IcxH8SX\n" "MF$m6wile%\n" "ilo3FURh9t\n" "d71hgGe5Vo\n" "KEr9u7CRtP\n" "CfUE4Fj$Ju\n" "aXSG5wIQor\n" "VTk2fmDlbx\n" "GHxBwpt0dN\n" "mYS2Q1zFi!\n" "qD0KiayFz4\n" "hT9FrGQ$dS\n" "5eKrEvnBZA\n" "gA$fXPUd2#\n" "Eoz8uqBART\n" "7wKEo6jJGX\n" "1p4Zj7Ssk2\n" "K#MX8Q61dr\n" "L%S2Kh7Q@r\n" "fwD6zy$NM@\n" "zyJPri5u7N\n" "MyAI!j2iz%\n" "9blWdD5!w@\n" "iw6Ef3dBLk\n" "JMYD1iHol2\n" "#M1OUJ0VDi\n" "e@78BCHLI%\n" "oeD1F!4ifz\n" "pCblno9zyJ\n" "FJKErsBTp6") 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