Clean and analyze employee exit survey

Hi everyone, I wrote this chunk of code. It seems to work to me, but I’m not extremely sure of its logic and I would appreciate if you could take a look and tell me if I make some mistake in the form or in the logic itself.

Screen Link:

My Code:

Replace this line with your code
```## convert the values into bool by creating a function 

def update_vals(value):
    if value == pd.isnull(value):
        return np.nan
    elif value == '-':
        return False
        return True

## apply the function to the cols

tafe_diss_factors = ['Contributing Factors. Job Dissatisfaction',
                     'Contributing Factors. Dissatisfaction']

## assign the boolean into a new column

tafe_resignations_up = tafe_resignations.copy()

tafe_resignations_up['dissatisfied'] = tafe_resignations[tafe_diss_factors].applymap(update_vals).any(axis=1,skipna=False)

What I expected to happen:

What actually happened: 

Replace this line with the output/error