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

/
/
gim

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"(?<FULLREQUEST>^(?<HOST>(?<PROTOCOL>(?:http)?s?:?\/\/)(?<DOMAIN>[^\/]+\/)|(?<RELATIVE>(?:\.*\/?)+))(?<PATH>[^\s]+\/)?(?<FILENAME>(?:(?<NAME>[^\/\s\.\?\#]+?)?(?<EXT>\.[^\s\?\#]*)?|(?:\/[^\/\s\?\#]+?)))(?<QUERYSTRING>\?[^\s\#]+)?(?<ANCHOR>\#\S+)?$)" test_str = ("Domain Name Root\n" "https://www.domain.com/\n" "https://www.domain.com/?with=queryString\n" "https://www.domain.com/#withAnchor\n" "https://www.domain.com/?with=queryString#andAnchor\n\n" "Full Domain Name With File\n" "https://www.domain.com/with-file\n" "https://www.domain.com/with-file?with=queryString\n" "https://www.domain.com/with-file#withAnchor\n" "https://www.domain.com/with-file?with=queryString#andAnchor\n\n" "Full Domain Name With File With Extension\n" "https://www.domain.com/file-with.ext\n" "https://www.domain.com/file-with.ext?with=queryString\n" "https://www.domain.com/file-with.ext#withAnchor\n" "https://www.domain.com/file-with.ext?with=queryString#andAnchor\n\n" "Full Domain Name With Path to File\n" "https://www.domain.com/some-path/to/a/file\n" "https://www.domain.com/some-path/to/a/file?with=queryString\n" "https://www.domain.com/some-path/to/a/file#withAnchor\n" "https://www.domain.com/some-path/to/a/file?with=queryString#andAnchor\n\n" "Full Domain Name With Path to File With Extension\n" "https://www.domain.com/some-path/to/a/file-with.ext\n" "https://www.domain.com/some-path/to/a/file-with.ext?with=queryString\n" "https://www.domain.com/some-path/to/a/file-with.ext\n" "https://www.domain.com/some-path/to/a/file-with.ext?with=queryString#andAnchor\n\n" "Dynamic Protocol Full Domain\n" "//www.domain.com/\n" "//www.domain.com/?with=queryString\n" "//www.domain.com/#withAnchor\n" "//www.domain.com/?with=queryString#andAnchor\n\n" "Dynamic Protocol (Full Domain) to File\n" "//www.domain.com/with-file\n" "//www.domain.com/with-file?with=queryString\n" "//www.domain.com/with-file#withAnchor\n" "//www.domain.com/with-file?with=queryString#andAnchor\n\n" "Dynamic Protocol (Full Domain) to File With Extension\n" "//www.domain.com/with-file-with.ext\n" "//www.domain.com/with-file-with.ext?with=queryString\n" "//www.domain.com/with-file-with.ext#withAnchor\n" "//www.domain.com/with-file-with.ext?with=queryString#andAnchor\n\n" "Dynamic Protocol (Full Domain), Path Leading to File\n" "//www.domain.com/with/path/to/file\n" "//www.domain.com/with/path/to/file?with=queryString\n" "//www.domain.com/with/path/to/file#withAnchor\n" "//www.domain.com/with/path/to/file?with=queryString#andAnchor\n\n" "Dynamic Protocol (Full Domain), Path Leading to File With Extension\n" "//www.domain.com/with/path/to/file-with.ext\n" "//www.domain.com/with/path/to/file-with.ext?with=queryString\n" "//www.domain.com/with/path/to/file-with.ext#withAnchor\n" "//www.domain.com/with/path/to/file-with.ext?with=queryString#andAnchor\n" "Root Relative File\n" "/some-root-file\n" "/some-root-file?with=queryString\n" "/some-root-file#withAnchor\n" "/some-root-file?with=queryString#andAnchor\n\n" "Root Relative File With Extension\n" "/root-file-with.ext\n" "/root-file-with.ext?with=queryString\n" "/root-file-with.ext#withAnchor\n" "/root-file-with.ext?with=queryString#andAnchor\n\n" "Root Path to File\n" "/some-root-path/to/a/file\n" "/some-root-path/to/a/file?with=queryString\n" "/some-root-path/to/a/file#withAnchor\n" "/some-root-path/to/a/file?with=queryString#andAnchor\n\n" "Root Path to File With Extension\n" "/some-root-path/to/a/file-with.ext\n" "/some-root-path/to/a/file-with.ext?with=queryString\n" "/some-root-path/to/a/file-with.ext#withAnchor\n" "/some-root-path/to/a/file-with.ext?with=queryString#andAnchor\n\n" "Relative (Same As Requestor) File\n" "./relative-to-requester-file\n" "./relative-to-requester-file?with=queryString\n" "./relative-to-requester-file#withAnchor\n" "./relative-to-requester-file?with=queryString#andAnchor\n\n" "Relative (Same As Requestor) File With Extension\n" "./relative-to-requester-file-with.ext\n" "./relative-to-requester-file-with.ext?with=queryString\n" "./relative-to-requester-file-with.ext#withAnchor\n" "./relative-to-requester-file-with.ext?with=queryString#andAnchor\n\n" "Relative (Same As Requestor) Path To File\n" "./relative-to-requester-path/to/a/file\n" "./relative-to-requester-path/to/a/file?with=queryString\n" "./relative-to-requester-path/to/a/file#withAnchor\n" "./relative-to-requester-path/to/a/file?with=queryString#andAnchor\n\n" "Relative (Same As Requestor) Path To File With Extension\n" "./relative-to-requester-path/to/a/file-with.ext\n" "./relative-to-requester-path/to/a/file-with.ext?with=queryString\n" "./relative-to-requester-path/to/a/file-with.ext#withAnchor\n" "./relative-to-requester-path/to/a/file-with.ext?with=queryString#andAnchor\n\n" "Relative (Above Requestor) File\n" "../relative-file-up\n" "../relative-file-up?with=queryString\n" "../relative-file-up#withAnchor\n" "../relative-file-up?with=queryString#andAnchor\n\n" "Relative (Above Requestor) File With Extension\n" "../relative-file-up-with.ext\n" "../relative-file-up-with.ext?with=queryString\n" "../relative-file-up-with.ext#withAnchor\n" "../relative-file-up-with.ext?with=queryString#andAnchor\n\n" "Relative (two Above Requestor) File\n" "../../relative-file-two-up\n" "../../relative-file-two-up?with=queryString\n" "../../relative-file-two-up#withAnchor\n" "../../relative-file-two-up?with=queryString#andAnchor\n\n" "Relative (two Above Requestor) File With Extension\n" "../../relative-file-two-up.ext\n" "../../relative-file-two-up.ext?with=queryString\n" "../../relative-file-two-up.ext#withAnchor\n" "../../relative-file-two-up.ext?with=queryString#andAnchor\n\n" "Relative (n Above Requestor) File\n" "../../../../../../../../relative-file-n-up\n" "../../../../../../../../relative-file-n-up?with=queryString\n" "../../../../../../../../relative-file-n-up#withAnchor\n" "../../../../../../../../relative-file-n-up?with=queryString#andAnchor\n\n" "Relative Path (Above Requestor) to File\n" "../relative-path/up/to/a/file\n" "../relative-path/up/to/a/file?with=queryString\n" "../relative-path/up/to/a/file#withAnchor\n" "../relative-path/up/to/a/file?with=queryString#andAnchor\n\n" "Relative Path (Above Requestor) to File With Extension\n" "../relative-path/up/to/a/file-with.ext\n" "../relative-path/up/to/a/file-with.ext?with=queryString\n" "../relative-path/up/to/a/file-with.ext#withAnchor\n" "../relative-path/up/to/a/file-with.ext?with=queryString#andAnchor\n\n" "Relative Path (Two Above Requestor) to File\n" "../../relative-path/two/up/to/a/file\n" "../../relative-path/two/up/to/a/file?with=queryString\n" "../../relative-path/two/up/to/a/file#withAnchor\n" "../../relative-path/two/up/to/a/file?with=queryString#andAnchor\n\n" "Relative Path (Two Above Requestor) to File With Extension\n" "../../relative-path/two/up/to/a/file-with.ext\n" "../../relative-path/two/up/to/a/file-with.ext?with=queryString\n" "../../relative-path/two/up/to/a/file-with.ext#withAnchor\n" "../../relative-path/two/up/to/a/file-with.ext?with=queryString#andAnchor\n\n" "Relative Path (n Above Requestor) to File\n" "../../../../../relative-path/n/up/to/a/file\n" "../../../../../relative-path/n/up/to/a/file?with=queryString\n" "../../../../../relative-path/n/up/to/a/file#withAnchor\n" "../../../../../relative-path/n/up/to/a/file?with=queryString#andAnchor\n\n" "Relative Path (n Above Requestor) to File With Extension\n" "../../../../../relative-path/n/up/to/a/file-with.ext\n" "../../../../../relative-path/n/up/to/a/file-with.ext?with=queryString\n" "../../../../../relative-path/n/up/to/a/file-with.ext#withAnchor\n" "../../../../../relative-path/n/up/to/a/file-with.ext?with=queryString#andAnchor\n") matches = re.finditer(regex, test_str, re.IGNORECASE | 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