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

/
/
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"(.*):\s(.*)" test_str = ("Name: Test Data 1\n" "Description: Lorem ipsum dolor sit amet, consectetur adipiscing elit. Donec feugiat nulla id nisi venenatis blandit.\n" " Donec blandit egestas orci, at tristique dui vehicula in. Maecenas fringilla fringilla enim, in pulvinar ex gravida\n" " in. Nam cursus facilisis ante, sed tristique nisl sagittis sed. In auctor felis id neque suscipit ullamcorper. Nunc\n" " faucibus elit sed metus vestibulum, ullamcorper pulvinar nisi auctor. Praesent sodales orci mauris, eget dapibus\n" " mauris sodales in. Ut iaculis, ante vitae ullamcorper semper, metus tortor auctor purus, eu convallis nulla lacus\n" " in tellus. Phasellus feugiat tempus neque, in fringilla nisi scelerisque sed. Donec elementum diam nec mattis dignissim.\n\n" "Name: Test Data 2\n" "Description: Lorem ipsum dolor sit amet, consectetur adipiscing elit. Donec feugiat nulla id nisi venenatis blandit.\n" " Donec blandit egestas orci, at tristique dui vehicula in. Maecenas fringilla fringilla enim, in pulvinar ex gravida\n" " in. Nam cursus facilisis ante, sed tristique nisl sagittis sed. In auctor felis id neque suscipit ullamcorper. Nunc\n" " faucibus elit sed metus vestibulum, ullamcorper pulvinar nisi auctor. Praesent sodales orci mauris, eget dapibus\n" " mauris sodales in. Ut iaculis, ante vitae ullamcorper semper, metus tortor auctor purus, eu convallis nulla lacus\n" " in tellus. Phasellus feugiat tempus neque, in fringilla nisi scelerisque sed. Donec elementum diam nec mattis dignissim.\n") 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