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

Code Generator

Generated Code

import re regex = re.compile(r"^(?=(.{0,1500}language[^\n]*\n[^\n]*\n[^\n]*))(?=(.{0,1500}experience[^\n]*\n[^\n]*\n[^\n]*))(?=(.{0,1500}acquire[^\n]*\n[^\n]*\n[^\n]*))", flags=re.MULTILINE | re.DOTALL) test_str = ("materials the in the case of language\n" "what was taken further than assumed sort\n" "of again though experiments but seems\n" "obvious is that the basic elements\n" "of language say concepts or words if\n" "there's any difference between them\n" "those must be primarily generated\n" "internally their complexity and richness\n" "is such that they can't possibly be\n" "acquired from experience they were what\n" "were called the common notions or innate\n" "ideas formed by some internal generative\n" "process that's structured in some\n" "fashion this and there was a good but\n" "about how this is done suggesting that\n" "what's involved is you start with but\n" "are now called gustave properties\n" "notions of casual relation notions of\n" "agency anthropomorphic perspectives all\n" "familiar with the way we perceive and\n" "think about the natural world\n" "so you see you you talk about a comet as\n" "aiming towards the Earth and fortunately\n") matches = regex.finditer(test_str) for match_num, match in enumerate(matches, start=1): print(f"Match {match_num} was found at {match.start()}-{match.end()}: {match.group()}") for group_num, group in enumerate(match.groups(), start=1): print(f"Group {group_num} found at {match.start(group_num)}-{match.end(group_num)}: {group}")

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