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"^\[assembly: AssemblyInformationalVersion\(\"(?P<version>[0-9]+(\.([0-9]+|\*)){1,3})\"\)\].*$", flags=re.MULTILINE) test_str = ("using System.Reflection;\n" "using System.Resources;\n" "using System.Runtime.InteropServices;\n\n" "// General Information about an assembly is controlled through the following \n" "// set of attributes. Change these attribute values to modify the information\n" "// associated with an assembly.\n" "[assembly: AssemblyTitle(\"MRC+\")]\n" "[assembly: AssemblyDescription(\"MRC+ Configuration\")]\n" "[assembly: AssemblyConfiguration(\"\")]\n" "[assembly: AssemblyCompany(\"Kongsberg Seatex AS\")]\n" "[assembly: AssemblyProduct(\"MRC+\")]\n" "[assembly: AssemblyCopyright(\"Copyright © Kongsberg Seatex AS 2009 - 2015\")]\n" "[assembly: AssemblyTrademark(\"\")]\n" "[assembly: AssemblyCulture(\"\")]\n\n" "// Setting ComVisible to false makes the types in this assembly not visible \n" "// to COM components. If you need to access a type in this assembly from \n" "// COM, set the ComVisible attribute to true on that type.\n" "[assembly: ComVisible(false)]\n\n" "// The following GUID is for the ID of the typelib if this project is exposed to COM\n" "[assembly: Guid(\"fd48eeca-4024-4955-aae1-e2279d13d262\")]\n\n" "// Version information for an assembly consists of the following four values:\n" "//\n" "// Major Version\n" "// Minor Version \n" "// Build Number\n" "// Revision\n" "//\n" "// You can specify all the values or you can default the Build and Revision Numbers \n" "// by using the '*' as shown below:\n" "// [assembly: AssemblyVersion(\"5.6.*\")]\n" "[assembly: AssemblyVersion(\"5.7.*\")]\n" "[assembly: AssemblyFileVersion(\"5.7.1\")]\n" "[assembly: AssemblyInformationalVersion(\"5.7.1.7\")] //Hurra!\n" "[assembly: NeutralResourcesLanguage(\"en\")]\n") match = regex.search(test_str) if match: print(f"Match 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