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"(.*[[:space:]]GRAVE:.*)" test_str = ("INFORMAZIONI: Parsing jar:file:/workarea/apache-tomcat/apache-tomcat-7.0.47_GA/webapps/GestioneAutorizzazioni/WEB-INF/lib/zkex-6.5.6.jar!/metainfo/zk/zk.xml\n" "lug 26, 2022 10:30:25 PM org.zkoss.zk.ui.sys.ConfigParser parse:269\n" "INFORMAZIONI: Parsing jar:file:/workarea/apache-tomcat/apache-tomcat-7.0.47_GA/webapps/GestioneAutorizzazioni/WEB-INF/lib/zkmax-6.5.6.jar!/metainfo/zk/zk.xml\n" "lug 26, 2022 10:30:25 PM org.zkoss.zk.ui.sys.ConfigParser parse:269\n" "INFORMAZIONI: Parsing jndi:/localhost/GestioneAutorizzazioni/WEB-INF/zk.xml\n" "lug 26, 2022 10:30:25 PM org.zkoss.zk.ui.http.WebManager <init>:172\n" "INFORMAZIONI: Parsing file:///workarea/apache-tomcat/tomcatGA/confapps/GestioneAutorizzazioni/zk-production.xml\n" "lug 26, 2022 10:30:25 PM org.zkoss.zk.ui.http.WebManager <init>:179\n" "GRAVE: File not found: file:///workarea/apache-tomcat/tomcatGA/confapps/GestioneAutorizzazioni/zk-production.xml\n" "lug 26, 2022 10:30:26 PM org.zkoss.zk.ui.metainfo.DefinitionLoaders parseLang:410\n" "AVVERTENZA: Component jasperreport ignored. Reason: unable to load org.zkoss.zkex.zul.Jasperreport due to java.lang.NoClassDefFoundError: net/sf/jasperreports/engine/JRDataSource\n\n" "Configuring Spring Security Core ...\n" "... finished configuring Spring Security Core\n\n" "amministrazione-database: doWithSpring\n" "anagrafe-soggetti: doWithSpring\n" "struttura-organizzativa: doWithSpring\n" "AmministrazioneDatabaseBootStrap: validate\n" "lug 26, 2022 10:30:56 PM org.apache.catalina.startup.HostConfig deployWAR\n" "INFORMAZIONI: Deploying web application archive /workarea/apache-tomcat/apache-tomcat-7.0.47_GA/webapps/probe.war\n" "lug 26, 2022 10:30:58 PM org.apache.catalina.startup.HostConfig deployWAR\n\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