сould someone please explain me why {6,}$
not {3,}$ ???

It is amazing to see 3 people come up with the same solution even with the comments. Cheaters Lookout.

I see, that's new to me :) Thank you

references for anyone interested:
https://docs.python.org/3/reference/lexical_analysis.html#string-literal-concatenation

https://stackoverflow.com/questions/8006551/how-to-split-long-regular-expression-rules-to-multiple-lines-in-python/8006611

it's not a multiline regex. It's based on "string continuation" instead: the interpreter concatenate all the strings when they are writen without any operator/separator, from one line to the other (and inside brackets, iirc)

Is this verbose regex? how did you manage to write it in mulit-lines with comments without using verbose flag?

how can this function search understand the characters in '' marks aren't they interpreted as string??