Question

I have about 100 fields I need to make sure have non-empty values. To do this I am doing:

if all([field1, field2, ...]):
    print 'ok'
else:
    raise

However, I’d like to know which fields have the empty values, so I can prompt the user to correct those. Is there a straightforward way to show which fields have the empty values in a large-scale validation, using all() or another method?

Answer 1

Assuming that you store the ‘fields’ in a dict:

>>> fields = {'a': 'A', 'b': '', 'c': 'C'}
>>> [key for key, value in fields.iteritems() if not value]
['b']

If it is a list and you want to know the indexes where the values are empty:

>>> fields = ['a', 'b', '', 'd']
>>> [index for index, value in enumerate(fields) if not value]
[2]