human
I wrote the below code

    def regexp_extract_lambda(value):
        if (not value):
            return None
        matches = method(pattern, value)
        if (not matches):
            return None
        return matches.group(group)
    return regexp_extract_lambda

What's a good function header?

=====
Here's a good function header?
assistant
#Here's a good function header.

def regexp_extract(pattern, method=re.match, group=1):