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

Substitution
Processing...

Code Generator

Language

Generated Code

import re regex = re.compile(r"^[\S\s]*?^([^][]*=)\[\[.*\]\]\K\]\R\1\[(.*)\]$", flags=re.MULTILINE) test_str = ("3 Forest Park Trolley - SOUTH=[[DEBALIVIERE GARAGE,[38.652722,-90.285656]]]\n" "3 Forest Park Trolley - SOUTH=[[PERSHING @ DEBALIVIERE EB,[38.648548,-90.284849]]]\n" "3 Forest Park Trolley - SOUTH=[[PERSHING @ CLARA EB,[38.648346,-90.282791]]]\n" "3 Forest Park Trolley - SOUTH=[[PERSHING @ BELT EB,[38.647911,-90.278559]]]\n" "3 Forest Park Trolley - SOUTH=[[5370 PERSHING EB,[38.64772,-90.276634]]]\n" "3 Forest Park Trolley - SOUTH=[[PERSHING @ UNION EB,[38.647512,-90.274466]]]\n" "3 Forest Park Trolley - SOUTH=[[FOREST PARK VISITORS CENTER WB,[38.643494,-90.283964]]]\n" "3 Forest Park Trolley - SOUTH=[[LAGOON @ GRAND BASIN WB,[38.64356,-90.291827]]]\n" "3 Forest Park Trolley - SOUTH=[[FINE ARTS @ ART MUSEUM SB,[38.639576,-90.294284]]]\n" "3 Forest Park Trolley - SOUTH=[[FINE ARTS @ ST LOUIS ZOO SB,[38.636939,-90.29116]]]\n" "3 Forest Park Trolley - SOUTH=[[FINE ARTS @ ST LOUIS ZOO SB,[38.636939,-90.29116]]]\n" "3 Forest Park Trolley - SOUTH=[[GOVERNMENT @ BOAT HOUSE EB,[38.639304,-90.284422]]]\n" "3 Forest Park Trolley - SOUTH=[[MCKINLEY @ MUNY THEATRE SB,[38.640333,-90.282175]]]\n" "3 Forest Park Trolley - SOUTH=[[UNION @ MUNY PARKING LOT EB,[38.636305,-90.279704]]]\n" "3 Forest Park Trolley - SOUTH=[[WELLS @ STEINBERG SKATING RINK EB,[38.638102,-90.27106]]]\n" "3 Forest Park Trolley - SOUTH=[[ST LOUIS SCIENCE CENTER LOOP,[38.631607,-90.2708]]]\n" "3 Forest Park Trolley - NORTH=[[ST LOUIS SCIENCE CENTER LOOP,[38.631607,-90.2708]]]\n" "3 Forest Park Trolley - NORTH=[[WELLS @ STEINBERG SKATING RINK WB,[38.638219,-90.271291]]]\n" "3 Forest Park Trolley - NORTH=[[UNION @ MUNY PARKING LOT WB,[38.636457,-90.279796]]]\n" "3 Forest Park Trolley - NORTH=[[CONCOURSE @ WORLDS FAIR PAVILION WB,[38.636589,-90.284272]]]\n" "3 Forest Park Trolley - NORTH=[[FINE ARTS @ ST LOUIS ZOO NB,[38.63707,-90.29103]]]\n" "3 Forest Park Trolley - NORTH=[[FINE ARTS @ ART MUSEUM NB,[38.639685,-90.294058]]]\n" "3 Forest Park Trolley - NORTH=[[LAGOON @ GRAND BASIN EB,[38.643417,-90.29192]]]\n" "3 Forest Park Trolley - NORTH=[[FOREST PARK VISITORS CENTER EB,[38.643343,-90.283906]]]\n" "3 Forest Park Trolley - NORTH=[[FINE ARTS @ ST LOUIS ZOO SB,[38.636939,-90.29116]]]\n" "3 Forest Park Trolley - NORTH=[[GOVERNMENT @ BOAT HOUSE EB,[38.639304,-90.284422]]]\n" "3 Forest Park Trolley - NORTH=[[PERSHING @ UNION WB,[38.647683,-90.274552]]]\n" "3 Forest Park Trolley - NORTH=[[5375 PERSHING WB,[38.647901,-90.276743]]]\n" "3 Forest Park Trolley - NORTH=[[PERSHING @ BELT WB,[38.648083,-90.278634]]]\n" "3 Forest Park Trolley - NORTH=[[PERSHING @ CLARA WB,[38.648491,-90.282634]]]\n" "3 Forest Park Trolley - NORTH=[[PERSHING @ DEBALIVIERE WB,[38.648726,-90.285022]]]\n" "3 Forest Park Trolley - NORTH=[[DEBALIVIERE GARAGE,[38.652722,-90.285656]]]") subst = ", \\2]" result = regex.sub(subst, test_str) if result: print(result)

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