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

Language

Generated Code

import re regex = re.compile(r"^(?P<unit_type>S)(?P<unit_size>\d{1,2})(?P<mounting_type>A|P)(?P<cracking_pressure>\d{1,2})(?P<sep_1>-)(?P<unit_series>1X)(?P<sep_2>/|=)(?P<pressure_rating_max>\d{1,3}|)(?P<surface_coating>J3|J5|)(?P<orifice_position>B|)(?P<orifice_diameter>\d{1,2}|)(?P<pipe_port>/2|/12|)(?P<special_version>(.|[0-9])*)$", flags=re.MULTILINE) test_str = ("S20P15-1X/\n" "S30P05-1X/V\n" "S30P02-1X/V\n" "S30P15-1X/V\n" "S30P30-1X/V\n" "S30P50-1X/V\n" "S30P00-1X/\n" "S30P05-1X/\n" "S30P15-1X/\n" "S30P30-1X/\n" "S30P50-1X/\n" "S10P00-1X/\n" "S10P05-1X/\n" "S10P05-1X/V\n" "S10P15-1X/\n" "S10P15-1X/V\n" "S10P30-1X/\n" "S10P30-1X/V\n" "S10P50-1X/\n" "S20P00-1X/\n" "S20P05-1X/\n" "S20P05-1X/SO74\n" "S20P05-1X/V\n" "S20P05-1X/VSO74\n" "S20P15-1X/SO74\n" "S20P15-1X/V\n" "S20P30-1X/\n" "S20P30-1X/SO74\n" "S20P30-1X/V\n" "S20P30-1X/VSO74\n" "S20P50-1X/\n" "S30P05-1X/VSO74\n" "S30P00-1X/SO74\n" "S30P15-1X/SO74\n" "S30P05-1X/SO74\n" "S25P15-1X/V\n" "S15P15-1X/V\n" "S15P15-1X/\n" "S25P15-1X/\n" "S10A05-1X/450J3\n" "S20A05-1X/450J3\n" "S30P05-1X=V\n" "S30P50-1X=V\n" "S10P05-1X=V\n" "S10P30-1X=V\n" "S20P05-1X=V\n" "S15A02-1X/450J3\n" "S20A02-1X/450J3\n" "S10A05-1X/450J3/12\n" "S20A05-1X/450J3B15/12\n" "S10A15-1X/450J3/12\n" "S20A30-1X/450J3\n" "S6A00-1X/450J3\n" "S6A02-1X/450J3\n" "S6A05-1X/450J3\n" "S6A15-1X/450J3\n" "S6A30-1X/450J3\n" "S6A50-1X/450J3\n" "S8A00-1X/450J3\n" "S8A02-1X/450J3\n" "S8A05-1X/450J3\n" "S8A15-1X/450J3\n" "S8A30-1X/450J3\n" "S8A50-1X/450J3\n" "S10A00-1X/450J3\n" "S10A02-1X/450J3\n" "S10A02-1X/450J3/12\n" "S10A15-1X/450J3\n" "S10A30-1X/450J3\n" "S10A50-1X/450J3\n" "S15A00-1X/450J3\n" "S15A05-1X/450J3B00\n" "S15A05-1X/450J3\n" "S15A15-1X/450J3\n" "S15A30-1X/450J3\n" "S15A50-1X/450J3\n" "S20A00-1X/450J3\n" "S20A02-1X/450J3/12\n" "S20A05-1X/450J3/12\n" "S20A15-1X/450J3\n" "S20A30-1X/450J3/12\n" "S20A50-1X/450J3\n" "S25A00-1X/420J3\n" "S25A02-1X/420J3\n" "S25A05-1X/420J3\n" "S25A15-1X/420J3\n" "S25A30-1X/420J3\n" "S25A50-1X/420J3\n" "S25A80-1X/420J3\n" "S30A00-1X/420J3\n" "S30A02-1X/420J3\n" "S30A05-1X/420J3\n" "S30A15-1X/420J3\n" "S30A30-1X/420J3\n" "S30A50-1X/420J3\n" "S30A80-1X/420J3\n" "S8A00-1X/450J3/12\n" "S8A05-1X/450J3/12\n" "S8A15-1X/450J3/12\n" "S8A30-1X/450J3/12\n" "S10A00-1X/450J3/12\n" "S10A30-1X/450J3/12\n" "S10A50-1X/450J3/12\n" "S15A00-1X/450J3/12\n" "S15A02-1X/450J3/12\n" "S15A05-1X/450J3/12\n" "S15A15-1X/450J3/12\n" "S15A30-1X/450J3/12\n" "S15A50-1X/450J3/12\n" "S20A00-1X/450J3/12\n" "S20A15-1X/450J3/12\n" "S20A50-1X/450J3/12\n" "S25A00-1X/420J3/12\n" "S25A02-1X/420J3/12\n" "S25A05-1X/420J3/12\n" "S25A15-1X/420J3/12\n" "S25A30-1X/420J3/12\n" "S25A50-1X/420J3/12\n" "S30A00-1X/420J3/12\n" "S30A02-1X/420J3/12\n" "S30A05-1X/420J3/12\n" "S30A15-1X/420J3/12\n" "S30A30-1X/420J3/12\n" "S30A50-1X/420J3/12\n" "S10A05-1X/450J3B08\n" "S10A05-1X/450J3B15\n" "S25A15-1X/420J3B10\n" "S25A50-1X/420J3B00\n" "S10A05-1X/450J3B00\n" "S20A05-1X/450J3B00\n" "S30A05-1X/420J3B00\n" "S30A05-1X/420J3B10\n" "S30A80-1X/420J3B12\n" "S15A05-1X/450J5/12\n" "S8A05-1X/450J3B03\n" "S30A50-1X/420J3B12\n" "S10A05-1X/450J3B10\n" "S30A30-1X/420J3B12\n" "S25A30-1X/420J3B12\n" "S15A05-1X/450J5\n" "S15A05-1X/450J5/12=AH\n" "S8A05-1X/450J3B08\n" "S10A05-1X=450J3\n" "S25A00-1X/420J3B10\n" "S10A05-1X/450J3B12\n" "S30A05-1X=420J3\n" "S10A50-1X/450J3/2\n" "S8A05-1X/450J3B05\n" "S15A50-1X/450J5\n" "S10A05-1X/450J3B10/12\n" "S25A50-1X/420J3B10\n" "S15A05-1X/450J3/2\n" "S15A05-1X/450J3B10\n" "S20A05-1X/450J3B10\n" "S25A05-1X=420J3/12\n" "S8A50-1X/450J5\n" "S8A05-1X/450J3B00\n" "S15A05-1X=450J3\n" "S25A05-1X=420J3\n" "S20A05-1X/450J3B15\n" "S6A05-1X=450J3\n" "S15A30-1X/450J3B10\n" "S20A05-1X/450J5\n" "S20A30-1X/450J3B15\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