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

r"
"

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"[0-9]*\.[0-9]+\.[0-9]+\.[0-9]" test_str = ("\n\n" "Interface IP-Address OK? Method Status Protocol\n" "TenGigabitEthernet1/1 unassigned YES NVRAM up up\n" "Te1/1.200 216.254.132.249 YES NVRAM up up\n" "Te1/1.201 10.201.120.173 YES NVRAM up up\n" "TenGigabitEthernet1/2 10.201.121.46 YES NVRAM up up\n" "TenGigabitEthernet1/3 unassigned YES NVRAM up up\n" "Te1/3.905 198.32.160.89 YES NVRAM up up\n" "Te1/3.908 206.130.10.3 YES NVRAM up up\n" "TenGigabitEthernet1/4 unassigned YES NVRAM administratively down down\n" "TenGigabitEthernet1/5 unassigned YES NVRAM up up\n" "Te1/5.98 216.254.131.1 YES NVRAM up up\n" "Te1/5.100 216.254.130.129 YES NVRAM administratively down down\n" "Te1/5.106 216.254.130.158 YES NVRAM administratively down down\n" "Te1/5.110 216.254.131.149 YES NVRAM up up\n" "Te1/5.111 216.254.131.117 YES NVRAM up up\n" "Te1/5.132 216.254.130.25 YES NVRAM administratively down down\n" "Te1/5.134 216.254.130.29 YES NVRAM up up\n" "Te1/5.205 216.254.141.153 YES NVRAM up up\n" "TenGigabitEthernet1/6 unassigned YES NVRAM up down\n" "TenGigabitEthernet1/7 unassigned YES NVRAM up up\n" "Te1/7.907 198.32.118.14 YES NVRAM up up\n" "TenGigabitEthernet1/8 10.201.121.154 YES NVRAM up up\n" "GigabitEthernet2/1 unassigned YES unset up up\n" "GigabitEthernet2/2 unassigned YES unset administratively down down\n" "GigabitEthernet2/3 unassigned YES unset administratively down down\n" "GigabitEthernet2/4 unassigned YES unset up up\n" "GigabitEthernet2/5 unassigned YES unset administratively down down\n") matches = re.search(regex, test_str) if matches: print ("Match was found at {start}-{end}: {match}".format(start = matches.start(), end = matches.end(), match = matches.group())) for groupNum in range(0, len(matches.groups())): groupNum = groupNum + 1 print ("Group {groupNum} found at {start}-{end}: {group}".format(groupNum = groupNum, start = matches.start(groupNum), end = matches.end(groupNum), group = matches.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