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

Code Generator

Language

Generated Code

import re regex = re.compile(r"(?<first><<<<<<< HEAD\n.*?)(?<========)|(?<second>(?=>>>>>>>).*?\n)", flags=re.DOTALL) test_str = ("<<<<<<< HEAD\n" "import { readdir } from \"fs\";\n" "import { createServer } from \"../src/server.js\";\n" "import Jasmine from 'jasmine';\n" "import dotenv from 'dotenv';\n\n" "const jasmine = new Jasmine();\n" "=======\n" "import { start } from \"../src/index.js\";\n\n" "import dotenv from 'dotenv';\n" "import { readdir } from \"fs\";\n" "import Jasmine from 'jasmine';\n" "import { resolve } from 'path';\n\n" ">>>>>>> c80322f... Refactor codebase. Removed ml parts into separate project.\n" "// jasmine.loadConfigFile(`tests/jasmine.json`);\n\n" "const importTests = () => {\n" " return new Promise((resolve, reject) => {\n" " readdir(`./tests`, (err, files) => {\n" " if (err) {\n" " reject(err);\n" " }\n" " files = files.filter(file => { \n" " return file.includes(`test.js`);\n" " });\n" " console.log(files);\n" " files = files.map(file => { \n" " const relativePath = `./${file}`;\n" " return import(relativePath)\n" " .catch(error => {\n" " console.error(`** Error loading ` + relativePath + `: `);\n" " console.error(error);\n" " process.exit(1);\n" " });\n" " });\n\n" " resolve(Promise.all(files));\n" " });\n" " });\n" "};\n\n" "const runTests = () => {\n" "<<<<<<< HEAD\n" " dotenv.config();\n\n" " importTests().then(() => {\n" " const server = createServer({\n" " useAuth: false,\n" " });\n\n" " server.options.port = 4040;\n" " process.env.GRAPHQL_ENDPOINT = `http://127.0.0.1:4040`;\n\n" " server.start(() => {\n" " console.log(`Test server is running on 127.0.0.1:${server.options.port}`);\n" " jasmine.execute();\n" " });\n" "=======\n" " const jasmine = new Jasmine();\n" " const environment = process.env.NODE_ENV || `staging`;\n\n" " dotenv.config({\n" " path: resolve(`../src/config/${environment}/.env`),\n" " });\n\n" " importTests().then(async () => {\n" " process.env.MONGODB_URIS = `mongodb+srv://f4a-shared-t95ry.gcp.mongodb.net/test`;\n" " process.env.GRAPHQL_ENDPOINT = `http://127.0.0.1:4040`;\n" " process.env.PORT = `4040`;\n" " await start();\n" " console.log(`Test server is running on 127.0.0.1:${server.port}`);\n" " jasmine.execute();\n" ">>>>>>> c80322f... Refactor codebase. Removed ml parts into separate project.\n" " });\n" "};\n" "runTests();") 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