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

/
/
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"((asia|europe|us|australia)|((north|south)(america|africa)))-((east|west|central|north|south)|((north|south)(east)))([0-9]{1,2})" test_str = ("(east|west|central|north)?(north|south)?(east)[0-9]{1,2}\n" "(east|west|central|north)(north|south)(east)[0-9]{1,2}\n\n" "(north|south)(america)\n\n" "FireStore Regions\n" "us-west1 oregon\n" "us-west2 Los Angeles\n" "us-west3 Tuz Gölü şehri\n" "us-west4 Las Vegas\n" "northamerica-northeast1 Montreal\n" "northafrica-west3\n" "southafrica-east1\n" "us-east1 Güney Carolina\n" "us-east4 Kuzey Virginia\n" "southamerica-east1 Sao Paulo\n" "europe-west2 Londra\n" "europe-west4\n" "europe-west3 Frankfurt\n" "europe-central2 Varşova\n" "europe-west6 Zürih\n" "asia-south1 Bombay\n" "asia-southeast1 Singapur\n" "asia-southeast2 Cakarta\n" "asia-east2 Hong Kong\n" "asia-east1 Tayvan\n" "asia-northeast1 Tokyo\n" "asia-northeast2 Osaka\n" "asia-northeast3 Seul\n" "australia-southeast1 Sidney\n" "australia-southeast2\n\n" "australia-southeast\n\n" "Function Regions\n\n" "asia-east1 (Tayvan)\n" "asia-east2 (Hong Kong)\n" "asia-northeast1 (Tokyo)\n" "asia-northeast2 (Osaka)\n" "europe-west1 (Belçika) \n" "europe-west2 (Londra)\n" "us-central1 (Iowa)\n" "us-east1 (Güney Karolina)\n" "us-east4 (Kuzey Virginia)\n" "us-west1 (Oregon)\n" "asia-northeast3 (Seul)\n" "asia-southeast1 (Singapur)\n" "asia-southeast2 (Cakarta)\n" "asia-south1 (Mumbai)\n" "australia-southeast1 (Sidney)\n" "europe-central2 (Varşova)\n" "europe-west3 (Frankfurt)\n" "europe-west6 (Zürih) \n" "northamerica-northeast1 (Montreal) \n" "southamerica-east1 (Sao Paulo) \n" "us-west2 (Los Angeles)\n" "us-west3 (Salt Lake City)\n" "us-west4 (Las Vegas)\n\n\n" "asia-east1 (Tayvan) us-west2 (Los Angeles) europe-west1 (Belçika)\n" "us-west3 (Salt Lake City) asia-northeast1 (Tokyo) southamerica-east1 (Sao Paulo)\n" "us-west4 (Las Vegas) asia-east2 (Hong Kong) northamerica-northeast1 (Montreal)\n" "europe-west2 (Londra) asia-south1 (Mumbai) europe-west3 (Frankfurt)\n" "us-central1 (Iowa) europe-central2 (Varşova) europe-west6 (Zürih)\n" "us-east1 (Güney Karolina)\n" "asia-northeast3 (Seul)\n" "us-east4 (Kuzey Virginia)\n" "australia-southeast1 (Sidney)\n" "us-west1 (Oregon)\n" "asia-southeast2 (Cakarta)\n" "asia-southeast1 (Singapur)") 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