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"<thing Class=\"Building(?:_[^\"]*)?\">(?:\R.*){2}\R.*\(.*,\h*\K104(?=\))", flags=re.MULTILINE) test_str = ("58 <thing Class=\"Plant\">\n" "59 <def>Plant_TreeOak</def>\n" "60 <id>Plant_TreeOak41339</id>\n" "61 <pos>(100, 0, 105)</pos>\n" "62 </thing>\n" "63 <thing Class=\"Building\">\n" "64 <def>Wall</def>\n" "65 <id>Wall28005</id> \n" "66 <pos>(101, 0, 105)</pos>\n" "68 </thing>\n" "69 <thing Class=\"Building\">\n" "70 <def>Wall</def>\n" "71 <id>Wall29667</id>\n" "72 <pos>(103, 0, 105)</pos>\n" "74 </thing>\n" "75 <thing Class=\"Building\">\n" "76 <def>Wall</def>\n" "77 <id>Wall28005</id>\n" "78 <pos>(101, 0, 104)</pos>\n" "80 </thing>\n" "81 <thing Class=\"Building_Door\">\n" "82 <def>Door</def>\n" "83 <id>Door642106</id>\n" "84 <pos>(102, 0, 104)</pos>\n" "86 </thing>\n" "87 <thing Class=\"Building\">\n" "88 <def>Wall</def>\n" "89 <id>Wall29667</id>\n" "90 <pos>(103, 0, 104)</pos>\n" "92 </thing>\n" "93 <thing Class=\"Plant\">\n" "94 <def>Plant_Grass</def>\n" "95 <id>Plant_Grass203219</id>\n" "96 <pos>(104, 0, 104)</pos>\n" "97 </thing>") subst = "103" 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