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"
"
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"(^(\d+%((?!\r\n)\s+))(\[((\w+)((\-\w+)?((?!\r\n)\s+)?(\w+)?((?!\r\n)\s+)?(\d+)?(\,)?(\d+)?(\.)?(\d?)((?!\r\n)\s+)?(k?B)?)?((?!\r\n)\s+)?(\w+)?\]))?(((((?!\r\n)\s+)\[)(.+)\])*(((?!\r\n)\s+)(\[)(.+))?(\r?\n)))" test_str = ("100% [Working]\n\n" "100% [Packages 201 kB] [Waiting for headers]\n\n" "100% [Waiting for headers]\n\n" "100% [Packages 201 kB] [Waiting for headers]\n\n" "100% [Sources 4,444 B] [Waiting for headers] [Waiting for headers]\n\n" "100% [Packages 39.0 kB] [Waiting for headers] [Waiting for headers]\n\n" "100% [Translation-en 904 kB] [Waiting for headers] [Waiting for headers]\n\n" "10% [InRelease gpgv 64.5 kB] [Waiting for headers] [Waiting for headers] [Waiti\n\n" "Reading package lists... 0%\n\n" "Reading package lists... 0%\n\n" "Reading package lists... 1%\n\n" "Reading package lists... 6%\n\n" "100% [Translation-en 4,149 kB] 17.4 MB/s 0s 100% [Working] 17.4 MB/s 0s 100%\n" "[Translation-en 409 kB] 17.4 MB/s 0s 100% [Working] 17.4 MB/s 0s 100%\n" "[Translation-en 21.2 kB] 17.4 MB/s 0s 100% [Working] 17.4 MB/s 0s 100%\n" "[Translation-en 18.6 MB] 17.4 MB/s 0s 100% [Working] 17.4 MB/s 0s\n\n" "100% [Working]\n\n" "100% [Packages 201 kB] [Waiting for headers]\n\n" "100% [Waiting for headers]\n\n" "Hit http://us.archive.ubuntu.com trusty-backports/multiverse i386 Packages\n\n\n" "100% [Working]\n\n" "100% [Packages 3,341 B] [Waiting for headers]\n\n" "100% [Waiting for headers]\n\n" "Hit http://us.archive.ubuntu.com trusty-backports/main Translation-en\n\n" "28% [Sources 507 kB] [1 InRelease 14.2 kB/64.4 kB 22%] [Waiting for headers] [W\n" "28% [Sources 507 kB] [InRelease gpgv 15.4 kB] [1 InRelease 14.2 kB/64.4 kB 22%]\n\n\n\n" "28% [Sources 507 kB] [InRelease gpgv 15.4 kB] [1 InRelease 14.2 kB/64.4 kB 22%]\n" "91% [InRelease gpgv 15.4 kB] [1 InRelease 14.2 kB/64.4 kB 22%] [Waiting for hea\n\n" "100% [Translation-en 363 kB] [4 Sources 221 kB/250 kB 89%] [Waiting for headers\n" "100% [4 Sources 221 kB/250 kB 89%] [Waiting for headers] [5 Packages 17.0 kB/23") 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