I am learning a lot of Regex with Python, and I am struggled with a regex for allow test cases where doesn't have consecutive 4 or more repeated chars, I have found easy solutions in Internet but I need evaluate the repeated chars excluding the "-" char, for example:
bic-hota // Valid
bichota // Valid
bichota1234 // Valid
bich222ota // Valid, sequence "222" with length of 3 is allowed
bichota2222 // Invalid because have "2222" and isn't allowed length of 4 or more
bichota22-22 // Invalid because have "2222" (ignore the '-') and isn't allowed length of 4 or more
In the last test case, you can see the sequence "22-22", I need ignore the "-" between the sequence for validate whole the sequence, and I have searched about how to solve this and I have use the Non-capture group (?:-?) but this doesn't works :(
^(?![\w]*([\w])(?:-?)\1{3,})[\w-] $
What is wrong with my regex and how to fix it?
Test cases: https://regexr.com/6p0ca
CodePudding user response：
You may use this regex:
^(?!.*(\w)(?:-?\1){3}).
RegEx Details:
^: Start(?!: Start negative lookahead.*: Match any length of characters(\w): Match a character and capture in group #1(?:-?\1){3}: Match optional-followed by back-reference to group #1. Repeat this group 3 times.
): End negative lookahead.: Match 1 of any characters
To allow only word characters and hyphens use:
^(?![\w-]*(\w)(?:-?\1){3})[\w-] $