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"\s{1,}\S{1,}$" test_str = ("ITGIS.COMP_OP_STN cos\n" "ITGIS.NS_DIVISIONS nsd\n" "ITGIS.COMP_OP_STN cos\n" "ITGIS.NSPD_RESP_ZONE nrz\n" "ITGIS.COMP_OP_STN cos\n" "PUBDATA.US_COUNTIES usc\n" "ITGIS.COMP_OP_STN cos\n" "PUBDATA.US_CITIES_BOUNDARIES uscb\n" "ITGIS.COMP_OP_STN cos\n" "nsdMatches nsd\n" "nrzMatches nrz\n" "cityBoundaryMatches\n" "countyMatches\n" "ITGIS.NSPD_LOCATIONS nl\n" "ITGIS.NS_DIVISIONS nd\n" "NFSAPP.CONTROL nfsac\n" "PUBDATA.US_CITIES c\n" "ENGXING.CI_LOCATIONANDCLASSIFICATION cils\n" "ITGIS.NS_DIVISIONS nsd\n" "ENGXING.CI_LOCATIONANDCLASSIFICATION cils\n" "ITGIS.NSPD_RESP_ZONE nrz\n" "ENGXING.CI_LOCATIONANDCLASSIFICATION cils\n" "PUBDATA.US_COUNTIES usc\n" "ENGXING.CI_LOCATIONANDCLASSIFICATION cils\n" "PUBDATA.US_CITIES_BOUNDARIES uscb\n" "ENGXING.DOTLIST dl\n" "INNER JOIN ENGXING.CI_LOCATIONANDCLASSIFICATION cils\n" "ENGXING.INVENTORY_QUE q\n" "nsdMatches nsd\n" "ENGXING.CI_OPERATINGRAILROAD cior\n" "nrzMatches nrz\n" "cityBoundaryMatches\n" "countyMatches\n" "ITGIS.NSPD_LOCATIONS nl\n" "ITGIS.NS_DIVISIONS nd\n" "ENG.ENG_CROSSING ec\n" "NFSAPP.CONTROL nfsac\n" "PUBDATA.US_CITIES c\n" "EGIS.ENG_MPMARK mp\n" "ITGIS.NS_DIVISIONS nsd\n" "EGIS.ENG_MPMARK mp\n" "ITGIS.NSPD_RESP_ZONE nrz\n" "EGIS.ENG_MPMARK mp\n" "PUBDATA.US_COUNTIES usc\n" "EGIS.ENG_MPMARK mp\n" "PUBDATA.US_CITIES_BOUNDARIES uscb\n" "EGIS.ENG_MPMARK mp\n" "nrzMatches nrz\n" "nsdMatches nsd\n" "cityBoundaryMatches\n" "countyMatches\n" "ITGIS.NSPD_LOCATIONS nl\n" "ITGIS.NS_DIVISIONS nd\n" "NFSAPP.CONTROL nfsac\n" "PUBDATA.US_CITIES c\n" "EGIS.ENG_SWITCH s\n" "ITGIS.NS_DIVISIONS nsd\n" "EGIS.ENG_SWITCH s\n" "ITGIS.NSPD_RESP_ZONE nrz\n" "EGIS.ENG_SWITCH s\n" "PUBDATA.US_COUNTIES usc\n" "EGIS.ENG_SWITCH s\n" "PUBDATA.US_CITIES_BOUNDARIES uscb\n" "EGIS.ENG_SWITCH s\n" "nsdMatches nsd\n" "nrzMatches nrz\n" "cityBoundaryMatches\n" "countyMatches\n" "ITGIS.NSPD_LOCATIONS nl\n" "ITGIS.NS_DIVISIONS nd\n" "NFSAPP.CONTROL nfsac\n" "PUBDATA.US_CITIES c\n" "EGIS.ENG_TOWER t\n" "ITGIS.NS_DIVISIONS nsd\n" "EGIS.ENG_TOWER t\n" "ITGIS.NSPD_RESP_ZONE nrz\n" "EGIS.ENG_TOWER t\n" "PUBDATA.US_COUNTIES usc\n" "EGIS.ENG_TOWER t\n" "PUBDATA.US_CITIES_BOUNDARIES uscb\n" "EGIS.ENG_TOWER t\n" "nsdMatches nsd\n" "nrzMatches nrz\n" "cityBoundaryMatches\n" "countyMatches\n" "ITGIS.NSPD_LOCATIONS nl\n" "ITGIS.NS_DIVISIONS nd\n" "PUBDATA.US_CITIES c\n" "ITGIS.COMP_AEI_SCNR s\n" "ITGIS.NS_DIVISIONS nsd\n" "ITGIS.COMP_AEI_SCNR s\n" "ITGIS.NSPD_RESP_ZONE nrz\n" "ITGIS.COMP_AEI_SCNR s\n" "PUBDATA.US_COUNTIES usc\n" "ITGIS.COMP_AEI_SCNR s\n" "PUBDATA.US_CITIES_BOUNDARIES uscb\n" "ITGIS.COMP_AEI_SCNR s\n" "nsdMatches nsd\n" "nrzMatches nrz\n" "cityBoundaryMatches\n" "countyMatches\n" "ITGIS.NSPD_LOCATIONS nl\n" "ITGIS.NS_DIVISIONS nd\n" "NFSAPP.CONTROL nfsac\n" "PUBDATA.US_CITIES c\n" "ITGIS.NSPD_LOCATIONS l\n" "ITGIS.NS_DIVISIONS nsd\n" "ITGIS.NSPD_LOCATIONS l\n" "ITGIS.NSPD_RESP_ZONE nrz\n" "ITGIS.NSPD_LOCATIONS l\n" "PUBDATA.US_COUNTIES usc\n" "ITGIS.NSPD_LOCATIONS l\n" "PUBDATA.US_CITIES_BOUNDARIES uscb\n" "ITGIS.NSPD_LOCATIONS l\n" "nsdMatches nsd\n" "nrzMatches nrz\n" "cityBoundaryMatches\n" "countyMatches\n" "ITGIS.NSPD_LOCATIONS nl\n" "PUBDATA.US_CITIES c\n" "NSPD.NSPD_POI poi\n" "ITGIS.NS_DIVISIONS nsd\n" "NSPD.NSPD_POI poi\n" "ITGIS.NSPD_RESP_ZONE nrz\n" "NSPD.NSPD_POI poi\n" "PUBDATA.US_COUNTIES usc\n" "NSPD.NSPD_POI poi\n" "PUBDATA.US_CITIES_BOUNDARIES uscb\n" "NSPD.NSPD_POI poi\n" "nsdMatches nsd\n" "nrzMatches nrz\n" "cityBoundaryMatches\n" "countyMatches\n" "ITGIS.NSPD_LOCATIONS nl\n" "PUBDATA.US_CITIES c\n" "ITGIS.ITGIS_MP100S mp\n" "ITGIS.NS_DIVISIONS nsd\n" "ITGIS.ITGIS_MP100S mp\n" "ITGIS.NSPD_RESP_ZONE nrz\n" "ITGIS.ITGIS_MP100S mp\n" "PUBDATA.US_COUNTIES usc\n" "ITGIS.ITGIS_MP100S mp\n" "PUBDATA.US_CITIES_BOUNDARIES uscb\n" "ITGIS.ITGIS_MP100S mp\n" "NFSAPP.CONTROL nfsac\n" "nrzMatches nrz\n" "nsdMatches nsd\n" "cityBoundaryMatches\n" "countyMatches\n" "ITGIS.NSPD_LOCATIONS nl\n" "ITGIS.NS_DIVISIONS nd\n" "PUBDATA.US_CITIES c\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