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

r"
"
gms

Test String

Code Generator

Language

Generated Code

import Foundation let pattern = #"(?P<error_msg>.*?)(?:exit\s+code:\s+)(?P<exit_code>\d+).(?:Stdout:)(?P<stdout>.*?)(?:Stderr:)(?P<stderr>.*?)(?:CUSTOM_EOF)"# let regex = try! NSRegularExpression(pattern: pattern, options: [.anchorsMatchLines, .dotMatchesLineSeparators]) let testString = #""" process "pipenv run pylint --rcfile .linting-configs/pylintrc ci/dagger/automation.py ci/dagger/async_interface.py ci/dagger/models/linting.py ci/dagger/models/config.py ci/dagger/linting.py ci/dagger/helper.py" did not complete successfully: exit code: 28 Stdout: o snake_case naming style (invalid-name) ************* Module models.linting ci/dagger/models/linting.py:9:0: C0115: Missing class docstring (missing-class-docstring) ci/dagger/models/linting.py:15:22: C0103: Argument name "v" doesn't conform to snake_case naming style (invalid-name) ci/dagger/models/linting.py:33:0: C0115: Missing class docstring (missing-class-docstring) ci/dagger/models/linting.py:44:4: C0115: Missing class docstring (missing-class-docstring) ci/dagger/models/linting.py:44:4: R0903: Too few public methods (0/2) (too-few-public-methods) ci/dagger/models/linting.py:33:0: R0903: Too few public methods (1/2) (too-few-public-methods) ci/dagger/models/linting.py:48:0: C0115: Missing class docstring (missing-class-docstring) ************* Module models.config ci/dagger/models/config.py:6:0: C0115: Missing class docstring (missing-class-docstring) ci/dagger/models/config.py:6:0: R0903: Too few public methods (0/2) (too-few-public-methods) ************* Module linting ci/dagger/linting.py:37:4: W0613: Unused argument 'client' (unused-argument) ci/dagger/linting.py:179:4: W0613: Unused argument 'client' (unused-argument) ci/dagger/linting.py:240:4: W0613: Unused argument 'client' (unused-argument) ci/dagger/linting.py:301:4: W0613: Unused argument 'client' (unused-argument) ci/dagger/linting.py:5:0: W0611: Unused import click (unused-import) ci/dagger/linting.py:7:0: W0611: Unused QueryError imported from dagger.exceptions (unused-import) ************* Module helper ci/dagger/helper.py:51:0: C0116: Missing function or method docstring (missing-function-docstring) ci/dagger/helper.py:88:0: C0115: Missing class docstring (missing-class-docstring) ci/dagger/helper.py:122:0: C0116: Missing function or method docstring (missing-function-docstring) ci/dagger/helper.py:133:19: W0212: Access to a protected member _raw_input of a client class (protected-access) ci/dagger/helper.py:1:0: W0611: Unused getenv imported from os (unused-import) ----------------------------------- Your code has been rated at 8.45/10 Stderr: CUSTOM_EOF """# let stringRange = NSRange(location: 0, length: testString.utf16.count) let matches = regex.matches(in: testString, range: stringRange) var result: [[String]] = [] for match in matches { var groups: [String] = [] for rangeIndex in 1 ..< match.numberOfRanges { let nsRange = match.range(at: rangeIndex) guard !NSEqualRanges(nsRange, NSMakeRange(NSNotFound, 0)) else { continue } let string = (testString as NSString).substring(with: nsRange) groups.append(string) } if !groups.isEmpty { result.append(groups) } } 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 Swift 5.2, please visit: https://developer.apple.com/documentation/foundation/nsregularexpression