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

# coding=utf8 # the above tag defines encoding for this document and is for Python 2.x compatibility import re regex = r"(?P<error_msg>.*?)(?:exit\s+code:\s+)(?P<exit_code>\d+).(?:Stdout:)(?P<stdout>.*?)(?:Stderr:)(?P<stderr>.*?)(?:CUSTOM_EOF)" test_str = ("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\n" "Stdout:\n" "o snake_case naming style (invalid-name)\n" "************* Module models.linting\n" "ci/dagger/models/linting.py:9:0: C0115: Missing class docstring (missing-class-docstring)\n" "ci/dagger/models/linting.py:15:22: C0103: Argument name \"v\" doesn't conform to snake_case naming style (invalid-name)\n" "ci/dagger/models/linting.py:33:0: C0115: Missing class docstring (missing-class-docstring)\n" "ci/dagger/models/linting.py:44:4: C0115: Missing class docstring (missing-class-docstring)\n" "ci/dagger/models/linting.py:44:4: R0903: Too few public methods (0/2) (too-few-public-methods)\n" "ci/dagger/models/linting.py:33:0: R0903: Too few public methods (1/2) (too-few-public-methods)\n" "ci/dagger/models/linting.py:48:0: C0115: Missing class docstring (missing-class-docstring)\n" "************* Module models.config\n" "ci/dagger/models/config.py:6:0: C0115: Missing class docstring (missing-class-docstring)\n" "ci/dagger/models/config.py:6:0: R0903: Too few public methods (0/2) (too-few-public-methods)\n" "************* Module linting\n" "ci/dagger/linting.py:37:4: W0613: Unused argument 'client' (unused-argument)\n" "ci/dagger/linting.py:179:4: W0613: Unused argument 'client' (unused-argument)\n" "ci/dagger/linting.py:240:4: W0613: Unused argument 'client' (unused-argument)\n" "ci/dagger/linting.py:301:4: W0613: Unused argument 'client' (unused-argument)\n" "ci/dagger/linting.py:5:0: W0611: Unused import click (unused-import)\n" "ci/dagger/linting.py:7:0: W0611: Unused QueryError imported from dagger.exceptions (unused-import)\n" "************* Module helper\n" "ci/dagger/helper.py:51:0: C0116: Missing function or method docstring (missing-function-docstring)\n" "ci/dagger/helper.py:88:0: C0115: Missing class docstring (missing-class-docstring)\n" "ci/dagger/helper.py:122:0: C0116: Missing function or method docstring (missing-function-docstring)\n" "ci/dagger/helper.py:133:19: W0212: Access to a protected member _raw_input of a client class (protected-access)\n" "ci/dagger/helper.py:1:0: W0611: Unused getenv imported from os (unused-import)\n\n" "-----------------------------------\n" "Your code has been rated at 8.45/10\n" "Stderr:\n" "CUSTOM_EOF") matches = re.finditer(regex, test_str, re.MULTILINE | re.DOTALL) for matchNum, match in enumerate(matches, start=1): print ("Match {matchNum} was found at {start}-{end}: {match}".format(matchNum = matchNum, start = match.start(), end = match.end(), match = match.group())) for groupNum in range(0, len(match.groups())): groupNum = groupNum + 1 print ("Group {groupNum} found at {start}-{end}: {group}".format(groupNum = groupNum, start = match.start(groupNum), end = match.end(groupNum), group = match.group(groupNum))) # 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