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Regular expression

Learn about the regular expressions in programming with examples explained in python.


link :
https://automatetheboringstuff.com/chapter7/

 summary 

  • The ? matches zero or one of the preceding group.
  • The * matches zero or more of the preceding group.
  • The + matches one or more of the preceding group.
  • The {n} matches exactly n of the preceding group.
  • The {n,} matches n or more of the preceding group.
  • The {,m} matches 0 to m of the preceding group.
  • The {n,m} matches at least n and at most m of the preceding group.
  • {n,m}? or *? or +? performs a nongreedy match of the preceding group.
  • ^spam means the string must begin with spam.
  • spam$ means the string must end with spam.
  • The . matches any character, except newline characters.
  • \d, \w, and \s match a digit, word, or space character, respectively.
  • \D, \W, and \S match anything except a digit, word, or space character, respectively.
  • [abc] matches any character between the brackets (such as a, b, or c).
  • [^abc] matches any character that isn’t between the brackets.

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