i saw a regular expression (?= (?:\d{5}|[A-Z]{2}))
in a python re example, and was very confused about the meaning of the ?:
.
I also see the python doc, there is the explain:
(?:...)
A non-capturing version of regular parentheses. Matches whatever regular expression is inside the parentheses, but the substring matched by the group cannot be retrieved after performing a match or referenced later in the pattern.
who can give me an example, and explain why it works, thanks!!