Python and Pandas NoneType error for empty list

Question

I have a form which takes a list of inputs via html (searchinput) and adds it to a query in python.

    searchterms = []
    searchterms = request.values.get('searchinput').strip().split(', ')
    filtered = pd.concat([df.query("Drug.str.contains('|'.join(@searchterms), na=False, case=False, regex=True)", engine='python')])
    return render_template('drugsafety.html', tables=[filtered.to_html(classes='data')], titles=['na', 'Drug List'])

This gives

AttributeError: 'NoneType' object has no attribute 'strip'

If I then feed in a value like searchterms = ["foobar"] it works and will even take the form inputs without error.

How can I get around this initial needing a value to boot it into life?

edit

    searchterms = []
    if searchterms is not None:
        searchterms = request.values.get('searchinput').strip().split(', ')
        filtered = pd.concat([ df.query("Drug.str.contains('|'.join(@searchterms), na=False, case=False, regex=True)", engine='python')])            
    else:  
        searchterms = ["Foo"]

Thanks for any help

It means that no value "searchinput" was found and get defaults to None instead. — Bram Vanroy
– Bram Vanroy, Commented Jun 18, 2021 at 8:32
Do you know of a way I can fix it? Putting a not none check doesnt change anything. — Dave
– Dave, Commented Jun 18, 2021 at 9:33

Andrej Kesely · Accepted Answer · 2021-06-18 09:54:22Z

1

Try to put default value ('') in .get:

# put `''` in .get():
searchterms = request.values.get('searchinput', '').strip().split(', ')

answered Jun 18, 2021 at 9:54

Andrej Kesely

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