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

Substitution

Processing...

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"^@(.*?){(.*?),((.|\n)*?)+(}}|\n})+$" test_str = ("@inproceedings{martens2010deep,\n" "title={Deep learning via Hessian-free optimization},\n" "author={Martens, James},\n" "booktitle={Proceedings of the 27th International Conference on Machine Learning (ICML-10)},\n" "pages={735--742},\n" "year={2010}\n" "}\n" "@article-journal{AAA,\n" " url = {http://www.example.com},\n" " year = {2016},\n" " month = {},\n" " publisher = {Elsevier},\n" " journal = {{AAA Journal}},\n" " author = {Austin Anderson and Austin Arnold},\n" " title = {{Nothing To See Here}},\n" "}\n" "@article-journal{ZZZ,\n" " url = {http://www.example.com},\n" " year = {2016},\n" " month = {},\n" " publisher = {Elsevier},\n" " journal = {{ZZZ Journal}},\n" " author = {Austin Zyzygy},\n" " title = {{Moving On Up}},\n" "}\n" "@article-journal{InstMed2001,\n" " url = {http://www.ncbi.nlm.nih.gov/pubmed/25057539},\n" " year = {2001},\n" " month = {},\n" " publisher = {{National Academy of Sciences}},\n" " doi = {10.17226/10027},\n" " volume = {},\n" " number = {},\n" " pages = {},\n" " pmid = {25057539},\n" " pmcid = {},\n" " journal = {{}},\n" " author = {{National Academy of Sciences}},\n" " title = {{Crossing the Quality Chasm: A New Health System for the 21st Century}},\n" "}\n" "@article-journal{Wallace2013,\n" " url = {http://apt.rcpsych.org/content/19/4/250},\n" " year = {2013},\n" " month = {July},\n" " publisher = {{Royal College of Psychiatrists}},\n" " doi = {10.1192/apt.bp.112.010389},\n" " volume = {19},\n" " number = {4},\n" " pages = {250-258},\n" " journal = {{BJPsych Advances}},\n" " author = {John Wallace},\n" " title = {{Lost in translation: transferring knowledge from research to clinical practice}},\n" "}\n" "@article-journal{Glasziou2005,\n" " url = {http://ebn.bmj.com/content/8/2/36.full},\n" " year = {2005},\n" " month = {},\n" " publisher = {{British Medical Journal}},\n" " doi = {10.1136/ebn.8.2.36},\n" " volume = {8},\n" " number = {},\n" " pages = {36-38},\n" " journal = {{Evidence Based Nursing}},\n" " author = {Paul Glasziou and Brian Haynes},\n" " title = {{The paths from research to improved health outcomes}},\n" "}\n" "@article-journal{Glasziou2011,\n" " url = {http://pmj.bmj.com/content/early/2011/06/29/pgmj.2010.116012.full.html},\n" " year = {2011},\n" " month = {June},\n" " publisher = {{British Medical Journal}},\n" " doi = {10.1136/pgmj.2010.116012},\n" " volume = {},\n" " number = {},\n" " pages = {},\n" " pmid = {},\n" " pmcid = {},\n" " journal = {{Postgraduate Medicine Journal}},\n" " author = {Sharon Mickan and Amanda Burls and Paul Glasziou},\n" " title = {{Patterns of 'leakage' in the utilisation of clinical guidelines: a systematic review}},\n" "}\n") subst = "{\\\"id\\\":\\\"${2}\\\",\\\"type\\\":${1},\\\"content\\\":[{${3}]}}" # You can manually specify the number of replacements by changing the 4th argument result = re.sub(regex, subst, test_str, 0, re.MULTILINE) if result: print (result) # 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