Regexes

Regular Expression Syntax

• General

  Choice
      Sequence | Sequence | ...
  Sequence
      Factor Quantifier ...
  Factor
      Groups
      Classes
      Characters & Escapes
  Quantifier
      * 0 or more times
      ? 0 or 1 times
      + 1 or more times
      {N} exactly N times
      {N,} N or more times
      {N,M} N through M times
  

• Groups

  Capturing Group
      (RegExp)
  Non-capturing Group
      (?:RegExp)
  Non-greedy Matching
      (RegExp?)
  Backreference
      \1 ... \N
  

• Classes

  Basic
      [12345], [abcde]
  Ranges
      [1-5], [a-e]
  Complements "Not In"
      [^6-9], [^f-z]
  Characters Needing Escape
      - / [ \ ] ^
  

• Chars

  Characters
      Any Unicode character except:
      /\ [] () {} ? + * | special/ctrl- char 
  Special Characters
      ^ Start of Line
      $ End of Line
      . Any character except end of line
  Escapes
      \d    Digit     \D    Non-digit
      \s    Whitespace     \S    Non-whitespace
      \w    "Word"     \W    Non-"Word"
      \n    New Line     \f    Formfeed
      \t    Tab     \r    Carriage Return
      \uNNNN Unicode where N is hex
  

Examples

• Chinese

  url(r'^update/(?P<uname>[^/]+)/$', 'update', name='update'),
  

• Any One

  url(r'^(?P<action>(cancel|confirm|success))/$', 'order_handle', name='order_handle'),
  

References

[1] GetHiFi, HiFi RegExp Tool