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"^[\S\s]*?^([^][]*=)\[\[.*\]\]\K\]\R\1\[(.*)\]$" 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]" # 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