Using glom, how can I concatenate optional strings?

Question

I have a dict containing a name in two parts:

target = {
    "givenName": "Elvis",
    "middleName": "Aron",
}

middleName is optional. I need to map to them one string, which is either givenName + ' ' + middleName if middleName is defined or just firstName. What is the canonical way to do this using glom?

Answer 1

The solution I've found so far is to use lambda and Coalesce. The below solution will work whether middleName is included or not:

    glom(target, Coalesce(
            lambda t: t["givenName"] + " " + t["middleName"],
            "givenName",
            skip_exc=KeyError),
    )