test = {'item1': None,
           'item2': None,
           'item3': None}

test = {'item1': 12,
           'item2': 'Ivanov',
           'item3': None}

if test['item1']:
        item_true = False
        for item in test:
            if item == 'item1':
                continue
            if test[item]:
                item_true = True
                break
        if not item_true:
            exit(1)

>>> def foo(dic,ignoreKey):
...     return any( [ dic[key] for key in dic if key != ignoreKey  ] )
>>> foo( {'item1': 12,
...       'item2': 'Ivanov',
...        'item3': None} ,
...     'item1')
True
>>> foo( {'item1': 12,
...        'item2': 0,
...        'item3': None} ,
...      'item1')
False

test = {'item1': None,
         'item2': None,
         'item3': None}
result=any(x==None for x in test.values())
print result

    if test['item1']:
        item_true = False
        for item in test:
            if item != 'item1':
                if test[item]:
                    item_true = True
                    break
        if not item_true:
            exit(1)

>>> а = 0
>>> if a:
...     print('yes')
...
yes
>>> a = ''
>>> if a:
...     print('yes')
...
>>> a = [1, 4, 5, 6]
>>> if a:
...     print('yes')
...
yes