python ::迭代嵌套的JSON结果

Question

iterating through JSON results can get quite confusing at times. say I have a function like so:

def get_playlist_owner_ids(query):

    results = sp.search(q=query, type='playlist')
    id_ = results['playlists']['items'][0]['owner']['id']
    return (id_)

I can fetch the id_ , it works.

but how do I iterate using a for i in x loop so I return ALL ids_ ?

Answer 1

results['playlists']['items'][0]['owner']['id']
                              ^___ this is a list index

Thus:

for item in results['playlists']['items']:
    print(item['owner']['id'])

It is often convenient to make intermediate variables in order to keep things more readable.

playlist_items = results['playlists']['items']
for item in playlist_items:
    owner = item['owner']
    print(owner['id'])

This is assuming I have correctly guessed the structure of your object based on only what you have shown. Hopefully, though, these examples give you some better ways of thinking about splitting up complex structures into meaningful chunks.

Answer 2

How about this? You can use generator to achieve your goal

def get_playlist_owner_ids(query):
    results = sp.search(q=query, type='playlist')
    for item in results['playlists']['items']:
        yield item['owner']['id']

Answer 3

You could iterate over results['playlists']['items'] , or, better yet, use list comprehension:

def get_playlist_owner_ids(query):

    results = sp.search(q=query, type='playlist')
    return [x['owner']['id'] for x in results['playlists']['items']]

Answer 4

In practice your document is something like this:

{ "playlists": {
    "items":[
        {"owner":{"id":"1"},...},                 
        {"owner":{"id":"2"},...},
        {"owner":{"id":"3"},...},
        ...,
}

So you have to loop over the list of items.

You can do something like this

ids = []
items = results['playlists']['items']
for item in items:
    ids.append(item['owner']['id'])

return ids

Or if you want to a one line:

ids = [item['owner']['id'] for owner in results['playlists']['items']]