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

/
/
gmi

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"\b(?!lv\b)\w+\b(?=(?:\s+lv)?\s+d(?:[iy]a|i)stolic d[yi]sfunction)" test_str = ("*AVR(1380),redo AVR (1396)due to AV prosthesis malfunction -Normal LV size with preserved systolic function(GEF= 50-55%)severe hypertrophy in apical segments maximom thickness=1.6cm with sparing of posterior wall, echo feature is mostly compatible with apical HCM-Mild LV diastolic dysfunction(Grade I)-Normal RV size with mild systolic dysfunction -Mild biatrial enlargemen (LAVI=40cc/m2 ,RAVI=33cc/m2)-Normal MVLs ; No MS;Mild to moderate MR-Mechanical prosthesis AV with good hemodynamic study (MG=6mmHg ,PG=11mmHg , AVACCT=63)No paravalvular leakage ;dilated ascending aorta=3.9cm ,(No visible dissection flap in ascending) -Normal PVLs ;No PS;Mild PI;Mean PAP=22mmHg-Normal TVLs ;No TS;Mild TR-Top Normal PAP-Normal IVC size and collapse-No pericardial effusion-IAS redundant\n" "-HOCM type III with significant resting LVOT obstruction(PPG=100 mmHg)-Normal LV size with good systolic function(EF=60%)-Mild diastolic dysfunction(grade I)-Normal RV size and systolic function-Severe SAM with moderate eccentric MR(ROA=0.25 cm2)-Mild TR-") matches = re.finditer(regex, test_str, re.MULTILINE | re.IGNORECASE) 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