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

r"
"
g

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"([A-Z0-9-]+)\.txt:NAME:\s\"module\s\w+\s([0-9/]+)\",\sDESCR:\s\"(.+)\"" test_str = ("RMAGPGE-PGBP01-01.txt:NAME: \"module R0\", DESCR: \"ASR 900 Route Switch Processor 2, Base Scale, 128Gbps\"\n" "RMAGPGE-PGIG01-01.txt:NAME: \"module R0\", DESCR: \"ASR 903 Route Switch Processor 1, Base Scale, 55Gbps\"\n" "RMAGPGE-PGIG01-01.txt:NAME: \"module R1\", DESCR: \"ASR 903 Route Switch Processor 1, Base Scale, 55Gbps\"\n" "RMAGPUI-PLIG01-01.txt:NAME: \"module R0\", DESCR: \"ASR 900 Route Switch Processor 2, Base Scale, 128Gbps\"\n" "RMAGPUI-PLIG01-01.txt:NAME: \"module R1\", DESCR: \"ASR 900 Route Switch Processor 2, Base Scale, 128Gbps\"\n" "RMAGPUI-PLMD00-01.txt:NAME: \"module R0\", DESCR: \"ASR 900 Route Switch Processor 2, Base Scale, 128Gbps\"\n" "RMAGPUI-PLMD00-01.txt:NAME: \"module R1\", DESCR: \"ASR 900 Route Switch Processor 2, Base Scale, 128Gbps\"\n" "RMAGPUI-PLMI00-01.txt:NAME: \"module R0\", DESCR: \"ASR 900 Route Switch Processor 2, Base Scale, 128Gbps\"\n" "RMAGPUI-PLMI00-01.txt:NAME: \"module R1\", DESCR: \"ASR 900 Route Switch Processor 2, Base Scale, 128Gbps\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module 0/RSP0/CPU0\", DESCR: \"ASR9K Route Switch Processor with 440G/slot Fabric and 12GB\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module 0/RSP1/CPU0\", DESCR: \"ASR9K Route Switch Processor with 440G/slot Fabric and 12GB\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module 0/0/CPU0\", DESCR: \"160G Modular Linecard, Service Edge Optimized\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module 0/0/0\", DESCR: \"ASR 9000 8-port 10GE Modular Port Adapter\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module mau 0/0/0/0\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module mau 0/0/0/1\", DESCR: \"10GBASE-LR SFP+ Module for SMF\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module mau 0/0/0/2\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module mau 0/0/0/3\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module mau 0/0/0/4\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module mau 0/0/0/5\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module mau 0/0/0/6\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module mau 0/0/0/7\", DESCR: \"10GBASE-LR SFP+ Module for SMF\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module 0/0/1\", DESCR: \"ASR 9000 8-port 10GE Modular Port Adapter\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module mau 0/0/1/2\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module mau 0/0/1/3\", DESCR: \"10GBASE-ZR SFP+, SMF 80km\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module mau 0/0/1/4\", DESCR: \"10GBASE-LR SFP+ Module for SMF\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module mau 0/0/1/5\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module mau 0/0/1/6\", DESCR: \"10GBASE-LR SFP+ Module for SMF\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module mau 0/0/1/7\", DESCR: \"10GBASE-LR SFP+ Module for SMF\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module 0/1/CPU0\", DESCR: \"160G Modular Linecard, Service Edge Optimized\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module 0/1/0\", DESCR: \"ASR 9000 8-port 10GE Modular Port Adapter\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module mau 0/1/0/0\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module mau 0/1/0/1\", DESCR: \"10GBASE-LR SFP+ Module for SMF\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module mau 0/1/0/2\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module mau 0/1/0/3\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module mau 0/1/0/4\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module mau 0/1/0/5\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module mau 0/1/0/6\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module mau 0/1/0/7\", DESCR: \"10GBASE-LR SFP+ Module for SMF\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module 0/1/1\", DESCR: \"ASR 9000 8-port 10GE Modular Port Adapter\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module mau 0/1/1/2\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module mau 0/1/1/3\", DESCR: \"10GBASE-ZR SFP+, SMF 80km\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module mau 0/1/1/4\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module mau 0/1/1/5\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module mau 0/1/1/6\", DESCR: \"10GBASE-ZR SFP+, SMF 80km\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module mau 0/1/1/7\", DESCR: \"10GBASE-LR SFP+ Module for SMF\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module 0/2/CPU0\", DESCR: \"160G Modular Linecard, Service Edge Optimized\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module 0/2/0\", DESCR: \"ASR 9000 8-port 10GE Modular Port Adapter\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module mau 0/2/0/0\", DESCR: \"10GBASE-LR SFP+ Module for SMF\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module mau 0/2/0/1\", DESCR: \"10GBASE-LR SFP+ Module for SMF\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module mau 0/2/0/2\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module mau 0/2/0/3\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module mau 0/2/0/4\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module mau 0/2/0/5\", DESCR: \"10GBASE-LR SFP+ Module for SMF\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module mau 0/2/0/6\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module mau 0/2/0/7\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module 0/3/CPU0\", DESCR: \"160G Modular Linecard, Service Edge Optimized\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module 0/3/0\", DESCR: \"ASR 9000 8-port 10GE Modular Port Adapter\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module mau 0/3/0/0\", DESCR: \"10GBASE-LR SFP+ Module for SMF\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module mau 0/3/0/1\", DESCR: \"10GBASE-LR SFP+ Module for SMF\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module mau 0/3/0/2\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module mau 0/3/0/3\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module mau 0/3/0/4\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module mau 0/3/0/5\", DESCR: \"10GBASE-LR SFP+ Module for SMF\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module mau 0/3/0/6\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-CGD01-01.txt:NAME: \"module mau 0/3/0/7\", DESCR: \"10GBASE-LR SFP+ Module for SMF\"\n" "RMAGRJO-GDL01-01.txt:NAME: \"module 0/RSP0/CPU0\", DESCR: \"ASR9K Route Switch Processor with 440G/slot Fabric and 12GB\"\n" "RMAGRJO-GDL01-01.txt:NAME: \"module 0/RSP1/CPU0\", DESCR: \"ASR9K Route Switch Processor with 440G/slot Fabric and 12GB\"\n" "RMAGRJO-GDL01-01.txt:NAME: \"module 0/0/CPU0\", DESCR: \"160G Modular Linecard, Service Edge Optimized\"\n" "RMAGRJO-GDL01-01.txt:NAME: \"module 0/0/0\", DESCR: \"ASR 9000 8-port 10GE Modular Port Adapter\"\n" "RMAGRJO-GDL01-01.txt:NAME: \"module mau 0/0/0/0\", DESCR: \"10GBASE-ZR SFP+, SMF 80km\"\n" "RMAGRJO-GDL01-01.txt:NAME: \"module mau 0/0/0/1\", DESCR: \"10GBASE-ZR SFP+, SMF 80km\"\n" "RMAGRJO-GDL01-01.txt:NAME: \"module mau 0/0/0/2\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-GDL01-01.txt:NAME: \"module mau 0/0/0/3\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-GDL01-01.txt:NAME: \"module mau 0/0/0/4\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-GDL01-01.txt:NAME: \"module mau 0/0/0/5\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-GDL01-01.txt:NAME: \"module mau 0/0/0/6\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-GDL01-01.txt:NAME: \"module mau 0/0/0/7\", DESCR: \"10GBASE-LR SFP+ Module for SMF\"\n" "RMAGRJO-GDL01-01.txt:NAME: \"module 0/0/1\", DESCR: \"ASR 9000 8-port 10GE Modular Port Adapter\"\n" "RMAGRJO-GDL01-01.txt:NAME: \"module mau 0/0/1/0\", DESCR: \"10GBASE-ZR SFP+, SMF 80km\"\n" "RMAGRJO-GDL01-01.txt:NAME: \"module mau 0/0/1/1\", DESCR: \"10GBASE-LR SFP+ Module for SMF\"\n" "RMAGRJO-GDL01-01.txt:NAME: \"module mau 0/0/1/2\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-GDL01-01.txt:NAME: \"module mau 0/0/1/3\", DESCR: \"10GBASE-LR SFP+ Module for SMF\"\n" "RMAGRJO-GDL01-01.txt:NAME: \"module mau 0/0/1/4\", DESCR: \"10GBASE-ZR SFP+, SMF 80km\"\n" "RMAGRJO-GDL01-01.txt:NAME: \"module mau 0/0/1/5\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-GDL01-01.txt:NAME: \"module mau 0/0/1/6\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-GDL01-01.txt:NAME: \"module mau 0/0/1/7\", DESCR: \"10GBASE-LR SFP+ Module for SMF\"\n" "RMAGRJO-GDL01-01.txt:NAME: \"module 0/1/CPU0\", DESCR: \"160G Modular Linecard, Service Edge Optimized\"\n" "RMAGRJO-GDL01-01.txt:NAME: \"module 0/1/0\", DESCR: \"ASR 9000 8-port 10GE Modular Port Adapter\"\n" "RMAGRJO-GDL01-01.txt:NAME: \"module mau 0/1/0/0\", DESCR: \"10GBASE-ZR SFP+, SMF 80km\"\n" "RMAGRJO-GDL01-01.txt:NAME: \"module mau 0/1/0/1\", DESCR: \"10GBASE-ZR SFP+, SMF 80km\"\n" "RMAGRJO-GDL01-01.txt:NAME: \"module mau 0/1/0/2\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-GDL01-01.txt:NAME: \"module mau 0/1/0/3\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-GDL01-01.txt:NAME: \"module mau 0/1/0/4\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-GDL01-01.txt:NAME: \"module mau 0/1/0/5\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-GDL01-01.txt:NAME: \"module mau 0/1/0/6\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-GDL01-01.txt:NAME: \"module mau 0/1/0/7\", DESCR: \"10GBASE-LR SFP+ Module for SMF\"\n" "RMAGRJO-GDL01-01.txt:NAME: \"module 0/1/1\", DESCR: \"ASR 9000 8-port 10GE Modular Port Adapter\"\n" "RMAGRJO-GDL01-01.txt:NAME: \"module mau 0/1/1/0\", DESCR: \"10GBASE-LR SFP+ Module for SMF\"\n" "RMAGRJO-GDL01-01.txt:NAME: \"module mau 0/1/1/1\", DESCR: \"10GBASE-LR SFP+ Module for SMF\"\n" "RMAGRJO-GDL01-01.txt:NAME: \"module mau 0/1/1/2\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-GDL01-01.txt:NAME: \"module mau 0/1/1/3\", DESCR: \"10GBASE-ZR SFP+, SMF 80km\"\n" "RMAGRJO-GDL01-01.txt:NAME: \"module mau 0/1/1/4\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-GDL01-01.txt:NAME: \"module mau 0/1/1/5\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-GDL01-01.txt:NAME: \"module mau 0/1/1/6\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-GDL01-01.txt:NAME: \"module mau 0/1/1/7\", DESCR: \"10GBASE-LR SFP+ Module for SMF\"\n" "RMAGRJO-MRT01-01.txt:NAME: \"module 0/RSP0/CPU0\", DESCR: \"ASR9K Route Switch Processor with 440G/slot Fabric and 12GB\"\n" "RMAGRJO-MRT01-01.txt:NAME: \"module 0/RSP1/CPU0\", DESCR: \"ASR9K Route Switch Processor with 440G/slot Fabric and 12GB\"\n" "RMAGRJO-MRT01-01.txt:NAME: \"module 0/0/CPU0\", DESCR: \"160G Modular Linecard, Service Edge Optimized\"\n" "RMAGRJO-MRT01-01.txt:NAME: \"module 0/0/0\", DESCR: \"ASR 9000 8-port 10GE Modular Port Adapter\"\n" "RMAGRJO-MRT01-01.txt:NAME: \"module mau 0/0/0/0\", DESCR: \"10GBASE-LR SFP+ Module for SMF\"\n" "RMAGRJO-MRT01-01.txt:NAME: \"module mau 0/0/0/1\", DESCR: \"10GBASE-LR SFP+ Module for SMF\"\n" "RMAGRJO-MRT01-01.txt:NAME: \"module mau 0/0/0/2\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-MRT01-01.txt:NAME: \"module mau 0/0/0/3\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-MRT01-01.txt:NAME: \"module mau 0/0/0/4\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-MRT01-01.txt:NAME: \"module mau 0/0/0/5\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-MRT01-01.txt:NAME: \"module mau 0/0/0/6\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-MRT01-01.txt:NAME: \"module mau 0/0/0/7\", DESCR: \"10GBASE-LR SFP+ Module for SMF\"\n" "RMAGRJO-MRT01-01.txt:NAME: \"module 0/0/1\", DESCR: \"ASR 9000 8-port 10GE Modular Port Adapter\"\n" "RMAGRJO-MRT01-01.txt:NAME: \"module mau 0/0/1/0\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-MRT01-01.txt:NAME: \"module mau 0/0/1/2\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-MRT01-01.txt:NAME: \"module mau 0/0/1/3\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-MRT01-01.txt:NAME: \"module mau 0/0/1/4\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-MRT01-01.txt:NAME: \"module mau 0/0/1/5\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-MRT01-01.txt:NAME: \"module mau 0/0/1/6\", DESCR: \"10GBASE-ER 1550nm SMF 40KM\"\n" "RMAGRJO-MRT01-01.txt:NAME: \"module mau 0/0/1/7\", DESCR: \"10GBASE-LR SFP+ Module for SMF\"\n" "RMAGRJO-MRT01-01.txt:NAME: \"module 0/1/CPU0\", DESCR: \"160G Modular Linecard, Service Edge Optimized\"\n" "RMAGRJO-MRT01-01.txt:NAME: \"module 0/1/0\", DESCR: \"ASR 9000 8-port 10GE Modular Port Adapter\"\n" "RMAGRJO-MRT01-01.txt:NAME: \"module mau 0/1/0/0\", DESCR: \"10GBASE-LR SFP+ Module for SMF\"\n") matches = re.finditer(regex, test_str) 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