Multiple spaces in a regular expression can make it hard to tell how many spaces should be matched. It’s more readable to use only one space and then indicate with a quantifier how many spaces are expected.

Noncompliant Code Example

r"Hello,   world!"

Compliant Solution

r"Hello, {3}world!"

Exceptions

If the extended modifier re.X or re.VERBOSE is set, whitespaces are ignored. In this case no issue should be triggered, because the whitespaces may be intended to improve readability.