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"
"
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"\[([\w\s*:/\-\.]*)\]\(([^()]+)\)" test_str = ("\n\n" "Let's see for example the [Diaspora*\n" "project](https://diasporafoundation.org/), a decentralized social network. The\n" "project is an alternative to Facebook and Twitter by promising Liberty,\n" "Privacy and Decentralization. This last word is the key problem. This kind of\n" "project finds its interests by multiplying what is called \"pods\" (servers with\n" "the software installed). However, in this case the installation process is\n" "very complicated, so even those who are comfortable with computers are not\n" "inclined to make the effort to install their own pod. See for example the\n" "[installation process for Ubuntu\n" "Trusty](https://wiki.diasporafoundation.org/Installation/Ubuntu/Trusty). The\n" "project offers a Vagrant installation too, but the documentation only admits\n" "that you know what you do, that you are a developer. If it is difficult to\n\n" "![https://diasporafoundation.org/assets/pages/about/network-\n" "distributed-e941dd3e345d022ceae909beccccbacd.png](data/images/network-\n" "distributed-e941dd3e345d022ceae909beccccbacd.png)\n\n" "_A pretty decentralized network (Source: <https://diasporafoundation.org/>)_\n\n\n\n" "Diaspora* is not the only project facing this problem. We can add\n" "[MediaGoblin](http://www.mediagoblin.org/pages/tour.html) to the list, an\n" "alternative to YouTube allowing you to host media (and [here it's deployment\n\n\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