Multiple conditions under `if` statement

I am trying to write a function that will classify goods in a given dataset (in a very straightforward way, i know).

It looks like:

def classifier(x):
    if ('smth' or 'smth' or 'smth') in x:
        return 'class1'
    elif ('smth' or 'smth' or 'smth') in x:
        return 'class2'

So, the problem is that some conditions do not work. When I try to check conditions separately - everything works. But in the function something goes wrong.

I use thing function with a pandas apply-method:

data['classes'] = data['subj'].apply(lambda x: classifier(x))