Regular Expressions 101

Save & Manage Regex

  • Current Version: 3
  • Save & Share
  • Community Library

Flavor

  • PCRE2 (PHP)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java
  • .NET 7.0 (C#)
  • Rust
  • PCRE (Legacy)
  • Regex Flavor Guide

Function

  • Match
  • Substitution
  • List
  • Unit Tests
Sponsors
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

Substitution
Processing...

Code Generator

Language

Generated Code

import re regex = re.compile(r""" \G #anclado a \A o fin de última coincidencia ( #Grupo 1: Caracteres previos [^\h\\'\v]*+ # Todo menos caracteres especiales (?: # Repetir infinitas veces (?: # Alternativas: (?!^)\h # a. espacio simple que no (?!\h|$) # está al ppio ni al final | \v # b. línea nueva | \\. # c. cualquier escape | '[^'\\]*+ # d. comillas (?:(?:''|\\.)[^'\\]*)* ' # ) # [^\h\\'\v]*+ # Seguido de más texto no especial )* # ) #(fin G1) (?: #Espacios: ^\h+ # a. al ppio de la línea | \h+(\h|$) # b. en el medio o al final ) # """, flags=re.MULTILINE | re.VERBOSE) test_str = (" select * , fooo , \n" " a, \n" "b,\n" "c\n" " from\n" "table\n" "where a = 'a b'\n" " or campo = 'borra los espacios \\'no?'\n" "and c = 1;") subst = "$1$2" result = regex.sub(subst, test_str) if result: 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 Python, please visit: https://docs.python.org/3/library/re.html