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
  • Match everything enclosed
    (?:...)
  • Capture everything enclosed
    (...)
  • 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

/
/

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"(?mis)^\bgeneral( #[0-9])?(.*?)^\s*$" test_str = ("General\n" "Complete name : C:\\Projects\\Foray\\MediaEngine\\SampleMedia\\flv\\small.flv\n" "Format : Flash Video\n" "File size : 296 KiB\n" "Duration : 5s 560ms\n" "Overall bit rate mode : Variable\n" "Overall bit rate : 436 Kbps\n" "Writing application : Lavf52.103.0\n\n" "Video\n" "Format : Sorenson Spark\n" "Codec ID : 2\n" "Duration : 5s 560ms\n" "Bit rate : 781 Kbps\n" "Width : 320 pixels\n" "Height : 240 pixels\n" "Display aspect ratio : 4:3\n" "Frame rate mode : Constant\n" "Frame rate : 25.000 fps\n" "Bit depth : 8 bits\n" "Bits/(Pixel*Frame) : 0.407\n" "Stream size : 530 KiB\n\n" "Audio\n" "Format : MPEG Audio\n" "Format version : Version 1\n" "Format profile : Layer 3\n" "Codec ID : 2\n" "Codec ID/Hint : MP3\n" "Duration : 5s 512ms\n" "Bit rate mode : Variable\n" "Bit rate : 63.8 Kbps\n" "Channel(s) : 1 channel\n" "Sampling rate : 44.1 KHz\n" "Compression mode : Lossy\n" "Stream size : 42.9 KiB (14%)\n\n\n") matches = re.search(regex, test_str) if matches: print ("Match was found at {start}-{end}: {match}".format(start = matches.start(), end = matches.end(), match = matches.group())) for groupNum in range(0, len(matches.groups())): groupNum = groupNum + 1 print ("Group {groupNum} found at {start}-{end}: {group}".format(groupNum = groupNum, start = matches.start(groupNum), end = matches.end(groupNum), group = matches.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