Regular Expressions 101

Save & Share

Flavor

  • PCRE2 (PHP >=7.3)
  • PCRE (PHP <7.3)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java 8
  • .NET 7.0 (C#)
  • Rust
  • Regex Flavor Guide

Function

  • Match
  • Substitution
  • List
  • Unit Tests

Tools

Sponsors
There are currently no sponsors. Become a sponsor today!
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

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"^((?!V2).)*- Master\s*$" test_str = ("AppMessages V2 - Dev\n" "AppMessages V2 - Master\n" "AWS - Octopus Release\n" "Bellhop Model V2 - Dev\n" "Bellhop Model V2 - Master\n" "BellHop Services V2 - Dev\n" "BellHop Services V2 - Master\n" "BellHop V2 - Dev\n" "BellHop V2 - Master\n" "BSG Log4j Extras V2 - Dev\n" "BSG Log4j Extras V2 - Master\n" "BSG-BOM - Dev\n" "BSG-BOM - Master\n" "BSG-BOM V2 - Dev\n" "BSG-BOM V2 - Master\n" "Core Model V2 - Dev\n" "Core Model V2 - Master\n" "Core Services V2 - Dev\n" "Core Services V2 - Master\n" "DealerLocator - Dev\n" "EMS Services V2 - Dev\n" "EMS Services V2 - Master\n" "Entitlements REST API V2 - Dev\n" "Entitlements REST API V2 - Master\n" "Entitlements Services V2 - Dev\n" "Entitlements Services V2 - Master\n" "Entitlements SOAP API V2 - Dev\n" "Entitlements SOAP API V2 - Master\n" "FlexNet Services - Dev\n" "FlexNet Services - Master\n" "GetNodeInfo BusSys-Build-Slave-01\n" "GetNodeInfo BusSys_Corp_Build_Slave\n" "GetNodeInfo Master\n" "Laipac Services V2 - Dev\n" "Laipac Services V2 - Master\n" "LDK Services V2 - Dev\n" "LDK Services V2 - Master\n" "LicenseAdmin - Dev\n" "LicenseAdmin - Master\n" "List All Jobs\n" "Lite Services V2 - Dev\n" "Lite Services V2 - Master\n" "LiteFlexNetIntegration V2 - Dev\n" "LiteFlexNetIntegration V2 - Master\n" "LiteIntegration - Dev\n" "LiteIntegration - Master\n" "Messaging Services V2 - Dev\n" "Messaging Services V2 - Master\n" "MTPConsumer - Dev\n" "MTPConsumer - Master\n" "OptionKeys - Dev\n" "OptionKeys - Master\n" "OptionKeysAPI - Dev\n" "OptionKeysAPI - Master\n" "Panther REST API V2 - Dev\n" "Pools API V2 - Dev\n" "Pools API V2 - Master\n" "Pools Model V2 - Dev\n" "Pools Model V2 - Master\n" "Pools Services V2 - Dev\n" "Pools Services V2 - Master\n" "Preconfigured API V2 - Dev\n" "Preconfigured API V2 - Master\n" "SCL Client V2 - Dev\n" "SCL Client V2 - Master\n" "SentinelCloud Services V2 - Dev\n" "SentinelCloud Services V2 - Master\n" "SubscriptionManager V2 - Dev\n" "SubscriptionManager V2 - Master\n" "TermsOfService - Master\n" "Test Support V2 - Dev\n" "Test Support V2 - Master\n" "Tid Services V2 - Dev\n" "Tid Services V2 - Master\n" "Upload templates to S3 - branch2Dev\n" "Upload templates to S3 - Dev\n" "Upload templates to S3 - Master\n" "Upload templates to S3 - Test\n" "VirtualWarehouse - Dev\n" "VirtualWarehouse - Master\n" "VirtualWarehouse Services V2 - Dev\n" "VirtualWarehouse Services V2 - Master\n" "VW Lite API - Dev\n" "VW Lite API - Master\n" "VW Remedy Events - Dev\n" "VW Remedy Events - Master\n" "VW Remedy Events Consumer - Dev\n" "VW Remedy Events Consumer - Master\n" "VW Remedy Events Lib - Dev\n" "VW Remedy Events Lib - Master\n" "VW Scheduled Tasks V2 - Dev\n" "VW Scheduled Tasks V2 - Master\n" "VW Sentinel V2 - Dev\n" "VW Sentinel V2 - Master\n" "VW Subscriptions V2 - Dev\n" "VW Subscriptions V2 - Master\n" "VW5 - Dev\n" "VW5 - Master\n" "WooCommerce API V2 - Dev\n" "WooCommerce API V2 - Master\n" "WooCommerce Model V2 - Dev\n" "WooCommerce Model V2 - Master\n" "WooCommerce Services V2 - Dev\n" "WooCommerce Services V2 - Master") matches = re.finditer(regex, test_str, re.MULTILINE) 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