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
Processing...

Test String

Code Generator

Language

Generated Code

import re regex = re.compile(r"\S+\s+\S+\s+\S+\s+\S+\s+\S+\s+(?P<host>[\w\-\.]*)(?::\d+)?\s+(?P<ip>\S+)\s+\S+\s+\S+\s+\[(?P<date>.*?)\s+(?P<timezone>.*?)\]\s+\"\S+\s+(?P<path>.*?)\s+\S+\"\s+(?P<status>\S+)\s+(?P<length>\S+)\s+\"(?P<referrer>.*?)\"\s+\"(?P<user_agent>.*?)\"\s+(?P<generation_time_secs>[.\d]+)") test_str = "Feb 6 09:33:42 ngx-01 acother: 115.231.222.14 - - [06/Feb/2016:09:33:42 +0100] \"GET http://zc.qq.com/cgi-bin/common/attr?id=260714&r=0.6027916056127199 HTTP/1.1\" 401 590 \"-\" \"Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; Trident/5.0; 360SE)\" 0.001" match = regex.search(test_str) if match: print(f"Match was found at {match.start()}-{match.end()}: {match.group()}") for group_num, group in enumerate(match.groups(), start=1): print(f"Group {group_num} found at {match.start(group_num)}-{match.end(group_num)}: {group}")

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