Python Regex: Check for match and capture groups

I want to ensure that a string matches a regular expression using an if statement, and store capture groups simultaneously. I think the following code shows what I want, but it is syntactically invalid. Is there a way to achieve the following elegantly?

yyyyq_format = "19984"

if regex_match = re.search("^(\d{4})(\d)$", yyyyq_format):
    found_q = regex_match[2]
else:
    raise ValueError("Format \"yyyyq\" is not followed.")

I know the following works (is this my only option?):

yyyyq_format = "19984"
regex_match = re.search("^(\d{4})(\d)$", yyyyq_format)

if regex_match:
    found_q = regex_match[2]
else:
    raise ValueError("Format \"yyyyq\" is not followed.")