Code | Explanation | Comment |
---|---|---|
. | Any single non-newline character | |
d | Any digit | [0-9] |
D | Any non-digit | [^d] |
s | Any whitespace character | [rntf] |
S | Any non-white space character | [^s] |
w | Any word character | Alphanumeric (a-z, A-Z, 0-9) and underscores (_) |
W | Any non-word character | [^w] |
^ | Position at the start of the string | Caret sign anchor, ex.: ^123 matches 1235123 |
$ | Position at the end of the string | Dollar sign anchor, matches an occurrence of character/character class/group at the end of a line. |
[] | Match only one out of several characters placed inside the square brackets | Character class |
[^] | Negated character class, match any character that is not in the square brackets | Complement |
[-] | Range of characters enclosed within the square brackets | Ex.: [a-z] , [0-9] |
{x} | Tool that matches exactly $$x$$ repetitions of character/character class/group | Quantifier, ex.: w{5} |
{x,y} | Tool that matches between $$[x,y]$$ repetitions of character/character class/group | Quantifier, The interval is inclusive! |
* | Matches 0 or more of character/character class/group | Quantifier |
+ | Matches 1 or more of character/character class/group | Quantifier |
b | Asserts position at a word boundary | Anchor |
() | Capturing group | round-brackets, parentheses |
(?:) | Non-capturing group | Group does need to capture its match. |
| | Match single items out of several possible items separated by pipe. | Alternations |
group_number | Match same text as referenced by group_number of captured group | Backreference, also possible to capture group that might not be matched at all. |
reg1(?=reg2) | Asserts whether a match with reg1 is immediately followed by reg2 is possible. | Positive lookahead only asserts whether match is possible or not, it does not return matches of reg2. |
reg1(?!reg2) | Asserts whether a match with reg1 is not immediately followed by reg2 is possible. | Negative lookahead only asserts whether match is possible or not, it does not return matches of reg2. |
Python Regex Cheat Sheet
Python regular expression cheatsheet and examples. Above visualization is a screenshot created using debuggex for the pattern r'bpar(en ro)?tb' From docs.python: re: A regular expression (or RE) specifies a set of strings that matches it; the functions. Typingmaster pro 7.1 0. Python Regex Cheatsheet. Regular Expression Basics. Any character except newline: a: The character a: ab: The string ab: a b: a or b: a.: 0 or more a's Escapes a.
Notes: Tinka tinka zara zara karaoke with lyrics.
Python Regex Cheatsheet Pdf
dd
should be shortened tod{2}
^dd(-?)dd(-?)dd(-?)dd$
vs.^d{2}(-?)(d{2}1){2}d{2}$
- think about it!- Forward referencing only in Java. Ex.:
^(2tic|(tac))+$
(only tactactic, tac, tic not directly next to tac), but also^tac(tactic|tac)+$
possible which is easier and more readable.