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]
  • Character class intersection
    [\w&&[^\d]]
  • 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-Fa-f0-9]{3}){1,2}|(?:rgb[(](?:\s*0*(?:\d\d?(?:\.\d+)?(?:\s*%)?|\.\d+\s*%|100(?:\.0*)?\s*%|(?:1\d\d|2[0-4]\d|25[0-5])(?:\.\d+)?)\s*(?:,(?![)])|(?=[)]))){3}|hsl[(]\s*0*(?:[12]?\d{1,2}|3(?:[0-5]\d|60))\s*(?:\s*,\s*0*(?:\d\d?(?:\.\d+)?\s*%|\.\d+\s*%|100(?:\.0*)?\s*%)){2}\s*|(?:rgba[(](?:\s*0*(?:\d\d?(?:\.\d+)?(?:\s*%)?|\.\d+\s*%|100(?:\.0*)?\s*%|(?:1\d\d|2[0-4]\d|25[0-5])(?:\.\d+)?)\s*,){3}|hsla[(]\s*0*(?:[12]?\d{1,2}|3(?:[0-5]\d|60))\s*(?:\s*,\s*0*(?:\d\d?(?:\.\d+)?\s*%|\.\d+\s*%|100(?:\.0*)?\s*%)){2}\s*,)\s*0*(?:\.\d+|1(?:\.0*)?)\s*)[)]|transparent|aqua(?:marine)?|azure|beige|bisque|black|blanchedalmond|blue(?:violet)?|(?:alice|dodger|cadet|midnight|powder|royal|sky|slate|steel)blue|(?:rosy|saddle|sandy)?brown|burlywood5|chartreuse|chocolate|coral|corn(?:flowerblue|silk)|crimson|cyan|dark(?:(?:slate)?blue|cyan|goldenrod|(?:olive|sea)?green|(?:slate)?gr[ae]y|khaki|magenta|orange|orchid|red|salmon|turquoise|violet)|deep(?:pink|skyblue)|firebrick|fuchsia|gainsboro|gold(?:enrod)?|(?:dim|slate)?gr[ae]y|(?:forest|lawn|spring)?green|greenyellow|honeydew|indigo|ivory|khaki|lavender(?:blush)?|lemonchiffon|light(?:(?:sky|steel)?blue|coral|cyan|goldenrodyellow|(?:slate)?gr[ae]y|green|pink|salmon|seagreen|yellow)|lime(?:green)?|linen|magenta|maroon|medium(?:aquamarine|(?:slate)?blue|orchid|purple|s(?:ea|pring)green|turquoise|violetred)|mintcream|mistyrose|moccasin|navy|oldlace|olive(?:drab)?|orange(?:red)?|orchid|pale(?:goldenrod|green|turquoise|violetred)|papayawhip|peachpuff|peru|(?:hot)?pink|plum|purple|(?:indian)?red|salmon|sea(?:green|shell)|sienna|silver|snow|tan|teal|thistle|tomato|turquoise|violet|wheat|whitesmoke|(?:antique|floral|ghost|navajo)?white|yellow(?:green)?)$", flags=re.MULTILINE) test_str = ("#0F0F0F\n" "#123\n" "#1234\n" "#ABC456\n" "#1234567\n" "rgb(1,2,3)\n" "rgb(1,2,)\n" "rgb(112233)\n" "rgb(255,249,199)\n" "rgb(256,249,199)\n" "rgb(255,249,199,)\n" "rgb( 100%, 199, 50%)\n" "rgb( 100%, 199%, 50%)\n" "rgb(1,2,3%,.5)\n" "rgba(1,2,3%,0.75)\n" "rgba(1,2,3%,.5)\n" "rgba(1,2,.5)\n" "rgba(1,2,3)\n" "rgba(1,249,100,1)\n" "rgba(1,249,100,1.0)\n" "rgba(1,249,100,1.1)\n" "rgba(255,256,255,1)\n" "rgba(1,249.5,100%,1)\n" "rgba(1,249.5,101%,1)\n" "hsl(360,2%,100%)\n" "hsl(361,2%,100%)\n" "hsl(,2%,100%)\n" "hsl(360,2%,)\n" "hsl(360,2%,0100.00%)\n" "hsl(360,2%,101%)\n" "hsla(180,2%,100%,0.5)\n" "hsla(180,2%,100%,)\n" "transparent\n" "blue\n" "palevioletred\n" "lightyellow") 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