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'^(?P<ip>\d{1,3}.\d{1,3}.\d{1,3}.\d{1,3}) - - \[(?P<date>.*)\] "(?P<request>.*?)" (?P<status>\d*) (?P<size>\d*) "(?P<referer>.*?)" "(?P<user_agent>.*?)".*$' test_str = ("192.0.102.40 - - [09/Apr/2018:06:26:33 -0400] \"HEAD /blog HTTP/1.1\" 301 0 \"-\" \"jetmon/1.0 (Jetpack Site Uptime Monitor by WordPress.com)\"\n" "192.0.102.40 - - [09/Apr/2018:06:26:33 -0400] \"HEAD /blog HTTP/1.1\" 301 0 \"-\" \"jetmon/1.0 (Jetpack Site Uptime Monitor by WordPress.com)\"\n" "198.199.64.224 - - [09/Apr/2018:06:26:33 -0400] \"POST /blog/wp-cron.php?doing_wp_cron=1523269593.5797910690307617187500 HTTP/1.1\" 499 0 \"-\" \"WordPress/4.9.5; https://ivoah.net/blog\"\n" "192.0.102.40 - - [09/Apr/2018:06:26:33 -0400] \"HEAD /blog/ HTTP/1.1\" 200 0 \"-\" \"jetmon/1.0 (Jetpack Site Uptime Monitor by WordPress.com)\"\n" "192.0.102.40 - - [09/Apr/2018:06:31:32 -0400] \"HEAD /blog HTTP/1.1\" 301 0 \"-\" \"jetmon/1.0 (Jetpack Site Uptime Monitor by WordPress.com)\"\n" "192.0.102.40 - - [09/Apr/2018:06:31:32 -0400] \"HEAD /blog HTTP/1.1\" 301 0 \"-\" \"jetmon/1.0 (Jetpack Site Uptime Monitor by WordPress.com)\"\n" "198.199.64.224 - - [09/Apr/2018:06:31:33 -0400] \"POST /blog/wp-cron.php?doing_wp_cron=1523269893.1204290390014648437500 HTTP/1.1\" 499 0 \"-\" \"WordPress/4.9.5; https://ivoah.net/blog\"\n" "192.0.102.40 - - [09/Apr/2018:06:31:33 -0400] \"HEAD /blog/ HTTP/1.1\" 200 0 \"-\" \"jetmon/1.0 (Jetpack Site Uptime Monitor by WordPress.com)\"\n" "192.0.102.40 - - [09/Apr/2018:06:36:39 -0400] \"HEAD /blog HTTP/1.1\" 301 0 \"-\" \"jetmon/1.0 (Jetpack Site Uptime Monitor by WordPress.com)\"\n" "192.0.102.40 - - [09/Apr/2018:06:36:39 -0400] \"HEAD /blog HTTP/1.1\" 301 0 \"-\" \"jetmon/1.0 (Jetpack Site Uptime Monitor by WordPress.com)\"\n" "198.199.64.224 - - [09/Apr/2018:06:36:39 -0400] \"POST /blog/wp-cron.php?doing_wp_cron=1523270199.4308791160583496093750 HTTP/1.1\" 499 0 \"-\" \"WordPress/4.9.5; https://ivoah.net/blog\"\n" "192.0.102.40 - - [09/Apr/2018:06:36:39 -0400] \"HEAD /blog/ HTTP/1.1\" 200 0 \"-\" \"jetmon/1.0 (Jetpack Site Uptime Monitor by WordPress.com)\"\n" "47.52.68.60 - - [09/Apr/2018:06:37:08 -0400] \"POST /blog/2016/05/13/mate-on-raspberry-pi/?share=email&nb=1 HTTP/1.1\" 302 5 \"https://ivoah.net/blog/2016/05/13/mate-on-raspberry-pi/?share=email&nb=1\" \"Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.2)\"\n" "47.52.68.60 - - [09/Apr/2018:06:37:09 -0400] \"GET /blog/2016/05/13/mate-on-raspberry-pi/?shared=email HTTP/1.1\" 200 30602 \"https://ivoah.net/blog/2016/05/13/mate-on-raspberry-pi/?share=email&nb=1\" \"Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.2)\"\n" "94.23.33.67 - - [09/Apr/2018:06:37:43 -0400] \"GET //wp-content/plugins/cherry-plugin/admin/css/cherry-admin-plugin.css HTTP/1.0\" 301 184 \"-\" \"Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/62.0.3202.94 Safari/537.36\"\n" "94.23.33.67 - - [09/Apr/2018:06:37:43 -0400] \"GET //wp-content/plugins/cherry-plugin/admin/css/cherry-admin-plugin.css HTTP/1.0\" 301 184 \"-\" \"Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/62.0.3202.94 Safari/537.36\"\n" "94.23.33.67 - - [09/Apr/2018:06:37:44 -0400] \"GET //wp-content/plugins/cherry-plugin/admin/css/cherry-admin-plugin.css HTTP/1.0\" 404 570 \"-\" \"Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/62.0.3202.94 Safari/537.36\"\n" "94.23.33.67 - - [09/Apr/2018:06:37:44 -0400] \"GET //wp-content/plugins/cherry-plugin/admin/css/cherry-admin-plugin.css HTTP/1.0\" 301 184 \"-\" \"Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/62.0.3202.94 Safari/537.36\"\n" "94.23.33.67 - - [09/Apr/2018:06:37:45 -0400] \"GET //wp-content/plugins/cherry-plugin/admin/css/cherry-admin-plugin.css HTTP/1.0\" 301 184 \"-\" \"Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/62.0.3202.94 Safari/537.36\"\n" "94.23.33.67 - - [09/Apr/2018:06:37:45 -0400] \"GET //wp-content/plugins/cherry-plugin/admin/css/cherry-admin-plugin.css HTTP/1.0\" 404 570 \"-\" \"Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/62.0.3202.94 Safari/537.36\"\n" "192.0.102.40 - - [09/Apr/2018:06:41:44 -0400] \"HEAD /blog HTTP/1.1\" 301 0 \"-\" \"jetmon/1.0 (Jetpack Site Uptime Monitor by WordPress.com)\"\n" "192.0.102.40 - - [09/Apr/2018:06:41:44 -0400] \"HEAD /blog HTTP/1.1\" 301 0 \"-\" \"jetmon/1.0 (Jetpack Site Uptime Monitor by WordPress.com)\"\n" "198.199.64.224 - - [09/Apr/2018:06:41:44 -0400] \"POST /blog/wp-cron.php?doing_wp_cron=1523270504.8351509571075439453125 HTTP/1.1\" 499 0 \"-\" \"WordPress/4.9.5; https://ivoah.net/blog\"\n" "192.0.102.40 - - [09/Apr/2018:06:41:44 -0400] \"HEAD /blog/ HTTP/1.1\" 200 0 \"-\" \"jetmon/1.0 (Jetpack Site Uptime Monitor by WordPress.com)\"\n" "207.244.149.74 - - [09/Apr/2018:06:45:38 -0400] \"GET /wp-content/plugins/wp-formgenerator/assets/js/simpleslider.js HTTP/1.1\" 404 341 \"https://ivoah.net/wp-content/plugins/wp-formgenerator/assets/js/simpleslider.js\" \"Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/42.0.2311.152 Safari/537.36\"\n" "54.36.148.188 - - [09/Apr/2018:06:45:44 -0400] \"GET /wp/audio/05042011.m4a HTTP/1.1\" 301 184 \"-\" \"Mozilla/5.0 (compatible; AhrefsBot/5.2; +http://ahrefs.com/robot/)\"\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