Get first item from nested list in glom

Question

from glom import glom, T

target = {
    "items": [
                {
                    "label": "valuation",
                    "value": [
                        "900 USD"
                    ]
                },]
}
spec = ('items',[T['value'][0]])
r = glom(target,spec)
print(r)

The above code returns a list, ['900 USD'] but I'd like to just get the content of that list, i.e the first item in the 'value' list. In this case the result should just be 900 USD

Part 2

from glom import glom, T, Check, SKIP

target = {
    "items": [
                {
                    "label": "valuation",
                    "value": [
                        "900 USD"
                    ]
                },
                {
                    "label": "other_info",
                    "value": [
                        "700 USD"
                    ]
                },]
}
spec = ({
    'answer': ('items', [Check('label', equal_to='valuation', default=SKIP)],([T['value'][0]]))
})
r = glom(target,spec)
print(r)

The above code results in {'answer': ['900 USD'] but I need to just return 900 USD.
Tried adding [0] at the end of the brackets but that didn't work.
Playing around with the T type also didn't result in what I'm looking for

Answer 1

I solved it by iterating over my result list and picking out the first element.
The following spec worked

spec = ({
    'answer': ('items', [Check('label', equal_to='valuation', default=SKIP)],( [T['value'][0]] ,Iter().first()) )
})

Notice the Iter().first() function call was added.

Answer 2

spec = {
    'answer': ('items', Iter().filter(
        lambda x: x['label'] is 'valuation'
    ).map('value.0').first())
}

Note, this is a streaming solution, thus performing better for larger datasets.

A string spec -- here 'value.0', the argument to the map method -- understands indexing into deep lists.

Depending on the specific logic that is desired this might work as well:

spec = {
    'answer': ('items', Iter().first(
        lambda x: x['label'] is 'valuation'
    ), 'value.0')
}

Here, we have combined filter logic with the restriction of a single result.