Conditionals with possible None values in List comprehension

Question

I have a xml file that lists speakers:

<speakerlist>
    <speaker>
        <title>Dr.</titel>
        <firstname>Bernd</firstname>
        <lastname>Baumann</lastname>
    </speaker>
    <speakerid="11003218">
        <firstname>Karsten</firstname>
        <lastname>Schneider</lastname>
        <info>(Erfurt)</info>
    </speaker>
    ...
<speakerlist>

Some of the speaker attributes are always given (firstname, lastname) while others are optional (title, info). I want to extract the names with the additional info in a straightforward way.

Just the name is easy, using beatifulsoup:

[speaker.find("firstname").text + " " +  speaker.find("lastname").text for speaker in speakerlist.find_all("speaker")]

But how can I prepend the title if existing? I tried

[
    speaker.find("title").text + " " + speaker.find("firstname").text + " " + speaker.find("lastname").text 
    if speaker.find("title").text is not None 
    else speaker.find("firstname").text + " " +  speaker.find("lastname").text
    for speaker in speakerlist.find_all("speaker")
]

but this throws

'NoneType' object has no attribute 'text'

when the title attribute does not exist. I understand why this happens, but I don't see a workaround.

Is there a nice and cohesive way for a one-liner to extract the information I want?

Answer 1

I see no good reason to try and squeeze this into an "one-liner" list comprehension.

def format_speaker_record(speaker):
    title_tag = speaker.find("title")
    title = (title.text if title_tag else None)
    firstname = speaker.find("firstname").text
    lastname = speaker.find("lastname").text
    if title:
        return f"{title} {firstname} {lastname}"
    return f"{firstname} {lastname}"


speakers = [format_speaker_record(speaker) for speaker in speakerlist.find_all("speaker")]