While the regex module will continue to be supported for backwards compatibility, there are several reasons to modify your code to use the re module. There are new operations in re, such as minimal matching, that cannot be performed using the regex module. The functions in the regex module return an integer giving the length or position of any match, or -1 if no match was found. To fix this problem, functions in the re module return a MatchObject instance, or None if the match failed.
Pattern objects now have no attributes that change after the object is created.
With the re. These programs can specify the re. The most common use of the translation string is to do a case-insensitive match by passing regex.casefold. The re equivalent is to pass re. In all these cases, if the tuple would only contain a single element, just that single string is returned.