+ 1
exemple in the python course "regular expressions - More Metacharacters"
I just read this exemple for the "?" meaning: import re pattern = r"ice(-)?cream" if re.match(pattern, "ice-cream"): print("Match 1") if re.match(pattern, "icecream"): print("Match 2") if re.match(pattern, "sausages"): print("Match 3") if re.match(pattern, "ice--ice"): print("Match 4") I think the "Match 4" would be with the string "ice--cream" and not with "ice--ice", isn't it?
2 odpowiedzi
+ 1
your pattern will match
ice-cream
icecream
(-)? read it as zero or one of the symbol -
Best to experiment on a site like
https://regex101.com/
for python or javascript regex
or
http://regexr.com/
for javascript regex
or
for general guidance
http://www.rexegg.com/
or for fun
https://regexcrossword.com/
0
I understand that but I just would talk about the (probably) mistake in the 4th exemple:
the pattern could be r"ice(-)?cream", r"ice(-)+cream" or r"ice(-)*cream", that could never match with "ice--ice"
:)