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
Processing...

Test String

Substitution
Processing...

Code Generator

Language

Generated Code

import re regex = re.compile(r"^\s+$\n^([ \t]+)Summary.*(?:\n\1[ \t]*\S.*)+", flags=re.MULTILINE) test_str = ("\n" "COMMENT REVIEWED REFSEQ: This record has been curated by NCBI staff. The\n" " reference sequence was derived from AC105339.9 and FJ695193.1.\n" " This sequence is a reference standard in the RefSeqGene project.\n" " \n" " Summary: Adaptor protein complex 3 (AP-3 complex) is a\n" " heterotrimeric protein complex involved in the formation of\n" " clathrin-coated synaptic vesicles. The protein encoded by this gene\n" " represents the beta subunit of the neuron-specific AP-3 complex and\n" " was first identified as the target antigen in human paraneoplastic\n" " neurologic disorders. The encoded subunit binds clathrin and is\n" " phosphorylated by a casein kinase-like protein, which mediates\n" " synaptic vesicle coat assembly. Defects in this gene are a cause of\n" " early-onset epileptic encephalopathy. [provided by RefSeq, Feb\n" " 2017].\n" " \n" " Another paragrph\n\n" "PRIMARY REFSEQ_SPAN PRIMARY_IDENTIFIER PRIMARY_SPAN COMP\n" " 1-35060 AC105339.9 88079-123138\n" " 35061-35259 FJ695193.1 1-199 c\n" " 35260-57628 AC105339.9 123337-145705\n") subst = "" result = regex.sub(subst, test_str) if result: print(result)

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