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

/
/
gm

Test String

Substitution

Processing...

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"^([A-Z][A-Z])" test_str = ("EPISODE 148: The Flea Party\n" " \n" "TAFFY\n" "Per-fect!\n" "BENTLEY\n" "Gotcha!\n" "MRS M\n" "Aaaah! I must ask Forsythe not to leave his kitchen cabinets lying around on the floor like this!\n" "MRS M\n" "Oh my! I hope my little cherub doesn’t have fleas or I’ll have to take that ribbon right off and put a flea collar on you!\n" "TAFFY\n" "Take the ribbon off?\n" "TAFFY\n" "Fleas? Please! This is just a common itch, I don’t have fleas.\n" "BENTLEY\n" "Oh no? Well you will my friend, you will. And I know just where to find them\n" "FLEA 1\n" "Cookie crumb?\n" "FLEA 2\n" "Don’t mind if I do.\n" "MISH\n" "Moldy macaroon?\n" "MASH\n" "Thank you kindly!\n" "MISH & MASH \n" "One for me, one for flea.\n" "MASH\n" "Enjoy, little dudes!\n" "MISH\n" "Ouch! Hey, what was that?!\n" "MASH\n" "Ow! Keep yer paws off my hairdo!\n" "MISH\n" "Me!? You’re the one pocking my hair!\n" "MASH\n" "Are you kidding me?\n" "MISH\n" "Liar!\n" "MASH\n" "What did you say?\n" "MISH\n" "I said…\n" "MASH\n" "Moldy macaroon?\n" "MISH\n" "Don’t mind if I do.\n" "FLEA\n" "HEY LET US OUT!!!\n" "BENTLEY\n" "Yeah, yeah, be patient\n" "FLEA 1\n" "Oh! Love that new host smell!\n" "You said it! Let’s settle here!\n" "BENTLEY\n" "Look! Fleas! Fleas!!! Whoo whoo whoo, fleas !\n" "MRS M\n" "Oh dear! you’re not scratching again are you?\n" "BENTLEY\n" "Go ahead, scratch it up! You know you want to.\n" "MRS M\n" "Delightful dinero, a discothèque!\n" "MRS M\n" "Like summer nights in Salamanca.\n" "MRS M\n" "Don’t be a party pooper, Bentley, dance with your little brother!\n" "Flea\n" "Earthquake!\n" "Flea\n" "Let’s move from this place!\n" "MRS M\n" "Coming!\n" "TAFFY\n" "Huh. I don’t itch anymore.\n" "BENTLEY\n" "Of COURSE you do! You’re covered in flea-AA!\n\n" "MRS M\n" "Bentley, now you?! And it looks like you might need more than a flea collar, you may need a HOT FLEA BATH.\n" "MRS M\n" "Sorry dear, what was that again? \n" "TAFFY\n" "Ah! That will teach you to start a flea fight\n" "MRS M\n" "Well if you can’t decide, why not buy BOTH yachts, dear?\n" "MRS HIGHCOST\n" "Hello? Are you still there?\n" "MRS M\n" "Oh sorry darling. Can you get them in platinum?\n" "TAFFY\n" "I love scratching\n" "TAFFY\n" "Scratch scratch scratch scratch\n" "MRS HIGHCOST\n" "So… Platinum or diamond then?\n" "MRS M\n" "Oh sorry dear, let’s have a look in the magazine\n" "TAFFY\n" "Here buddy, this will help!\n" "BENTLEY\n" "Oh! Itchy wool!\n" "MRS M \n" "Well of course matching helicopters! What are we? Cave people?\n" "FORSYTHE\n" "I’ve nearly achieved...PERFECTION!\n" "FORSYTHE\n" "Out of my kitchen you fleabag!\n" "MRS M \n" "Animal control, I have a flea emergency!\n" "MASH\n" "There you are! We found you!\n" "TAFFY\n" "Found me?\n" "MASH\n" "Not you-– them!\n" "MISH & MASH\n" "Welcome home fellas!\n" "See ya!\n" "ANIMAL CONTROL \n" "This is worse than the Itchy Dingo Disaster of ‘05.\n" "TAFFY\n" "Showtime!\n" "MRS M \n" "Oh my hair!\n" "Oh! What a wonderful haircut for this summer! \n" "Thank you Taffy-Waffy\n") subst = " \\1" # You can manually specify the number of replacements by changing the 4th argument result = re.sub(regex, subst, test_str, 0, re.MULTILINE) if result: print (result) # 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