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"(?:(?# Pattern before filename\n" r" )(?:\[download\] )?Destination: (?#\n" r")|(?#\n" r" )\[download\] (?#\n" r")|(?#\n" r" )Adding metadata to \"(?#\n" r"))(?#\n" r")((?# CAPTURE GROUP: filename pattern\n" r" )\/?[^\/\\\n]+(?:\/|\\)(?# Capture first folder\n" r" )(?:(?#\n" r" )[^\n\.]*(?# Stop capturing if point, to check\n" r" )(?!\.f\d{1,4}\.(?:webm|mov|mp4))(?# Checking this is not a partial download\n" r" )\.(?# Can now capture the point\n" r" ))+(?#\n" r" )(?:webm|mov|mp4)(?#\n" r"))(?#\n" r")\n?") test_str = ("=============================\n" " GOOD TESTS\n" "=============================\n" "[download] /root/.local/share/ICONO_TESTS/1678445152615210072_0.33914607510068406/yt-videos/BURGER KLEAN - 1080.mp4 has already been downloaded\n" "[download] /root/.local/share/ICONO_TESTS/small/yt-videos/hello.mp4 has already been downloaded\n" "[download] /root/local/share/ICONO_TESTS/small/yt-videos/hello.mp4 has already been downloaded\n" "Destination: /root/.local/share/ICONO_TESTS/1678445152615210072_0.33914607510068406/yt-videos/Hi Anxiety： Lana Condor - 1080.mp4\n" "[download] Destination: /root/.local/share/ICONO_TESTS/1678445152615210072_0.33914607510068406/yt-videos/#histoire #vrai #fyp #foryou #pourtoi #fyp - NA.mp4\n" "Destination: C:/Users/Adrien/AppData/Local/ICONO/ICONO_TESTS/yt-videos/ICONO in a minute or so. - 1080.webm\n" "Destination: C:/Users/Adrien/AppData/Local/ICONO/ICONO_TESTS/yt-videos/ICONO in a minute or so - 1080.webm\n" "Destination: C:/Users/Adrien/AppData/Local/ICONO/ICONO_TESTS/yt-videos/ICONO.webm\n" "Destination: C:/Users/Adrien/AppData/Local/ICONO/ICONO_TESTS/yt-videos/ICONO_123.webm\n" "Destination: C:/Users/Adrien/AppData/Local/ICONO/ICONO_TESTS/yt-videos/ICONO_1.2.3.mp4\n" "xxx Destination: C:/Users/Adrien/AppData/Local/ICONO/ICONO_TESTS/yt-videos/ICONO in a minute or so - 1080.mov\n" "xxx Adding metadata to \"C:/Users/Adrien/AppData/Local/ICONO/ICONO_TESTS/yt-videos/ICONO in a minute or so - 1080.mov\"\n" "[Metadata] Adding metadata to \"C:/Users/Adrien/AppData/Local/ICONO/ICONO_TESTS/yt-videos/ICONO in a minute or so - 1080.mov\"\n" "[Metadata] Adding metadata to \"C:/Users/Adrien/AppData/Local/ICONO/ICONO_TESTS/yt-videos/ICONO in a minute or so - 1080.mov\"\n" "[Metadata] Adding metadata to \"/home/ezalos/.local/share/ICONO_TESTS/yt-videos/ICONO in a minute or so. - 1080.mov\"\n" "[Metadata] Adding metadata to \"/home/ezalos/.local/share/ICONO_TESTS/yt-videos/ICONO in a minute or so. - 1080.mov\"\n\n" "Adding metadata to \"C:\\Users\\Adrien\\AppData\\Local\\ICONO\\ICONO_TESTS\\1678715744635004900_0.6505223019081934\\yt-videos\\BURGER KLEAN - 1080.mp4\n\n" "=============================\n" " BAD TESTS\n" "=============================\n" " def test_download(browser: Chrome):\n" " app_actions = AppActions(browser, test_name=\"test_download\")\n" " app_actions.screenshot()\n" " for url in url_to_test:\n" " file_path = app_actions.download_video(url)\n" "> assert os.path.isfile(file_path)\n" "E AssertionError: assert False\n" "E + where False = <function isfile at 0x000002D095AFF160>('C:/Users/Adrien/AppData/Local/ICONO/ICONO_TESTS/yt-videos/ICONO in a minute or so. - 1080.f248.webm')\n" "E + where <function isfile at 0x000002D095AFF160> = <module 'ntpath' from 'C:\\\\Users\\\\Adrien\\\\mambaforge\\\\envs\\\\ICONO-prod\\\\lib\\\\ntpath.py'>.isfile\n" "E + where <module 'ntpath' from 'C:\\\\Users\\\\Adrien\\\\mambaforge\\\\envs\\\\ICONO-prod\\\\lib\\\\ntpath.py'> = os.path\n" "Destination: C:/Users/Adrien/AppData/Local/ICONO/ICONO_TESTS/yt-videos/ICONO in a minute or so - 1080.f248.webm\n" "Destination: C:/Users/Adrien/AppData/Local/ICONO/ICONO_TESTS/yt-videos/ICONO in a minute or so - 1080.f248.mov\n" "DEBUG : 35954 ms [Thread 140114533140224] src.back.download.ytdlp.execute_command:25 || STDOUT: [download] 0.1% of ~ 966.70KiB at 43.60KiB/s ETA 00:22 (frag 0/1)\n" "DEBUG : 35954 ms [Thread 140114533140224] src.back.download.ytdlp.execute_command:25 || STDOUT: [download] 0.3% of ~ 966.70KiB at 127.60KiB/s ETA 00:07 (frag 0/1)\n" "DEBUG : 35954 ms [Thread 140114533140224] src.back.download.ytdlp.execute_command:25 || STDOUT: [download] 0.7% of ~ 966.70KiB at 291.21KiB/s ETA 00:03 (frag 0/1)\n" "DEBUG : 35954 ms [Thread 140114533140224] src.back.download.ytdlp.execute_command:25 || STDOUT: [download] 1.6% of ~ 966.70KiB at 610.67KiB/s ETA 00:01 (frag 0/1)\n" "DEBUG : 35954 ms [Thread 140114533140224] src.back.download.ytdlp.execute_command:25 || STDOUT: [download] 3.2% of ~ 966.70KiB at 1.21MiB/s ETA 00:00 (frag 0/1)\n" "DEBUG : 35954 ms [Thread 140114533140224] src.back.download.ytdlp.execute_command:25 || STDOUT: [download] 6.5% of ~ 966.70KiB at 2.30MiB/s ETA 00:00 (frag 0/1)\n" "DEBUG : 35954 ms [Thread 140114533140224] src.back.download.ytdlp.execute_command:25 || STDOUT: [download] 13.1% of ~ 966.70KiB at 4.33MiB/s ETA 00:00 (frag 0/1)\n" "DEBUG : 35954 ms [Thread 140114533140224] src.back.download.ytdlp.execute_command:25 || STDOUT: [download] 26.4% of ~ 966.70KiB at 8.06MiB/s ETA 00:00 (frag 0/1)\n" "DEBUG : 35954 ms [Thread 140114533140224] src.back.download.ytdlp.execute_command:25 || STDOUT: [download] 52.9% of ~ 966.70KiB at 14.72MiB/s ETA 00:00 (frag 0/1)\n" "DEBUG : 35955 ms [Thread 140114533140224] src.back.download.ytdlp.execute_command:25 || STDOUT: [download] 100.0% of ~ 966.70KiB at 25.08MiB/s ETA 00:00 (frag 0/1)\n" "DEBUG : 35955 ms [Thread 140114533140224] src.back.download.ytdlp.execute_command:25 || STDOUT: [download] 100.0% of ~ 966.70KiB at 24.67MiB/s ETA 00:00 (frag 1/1)\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