如何在推文中不包含任何值的情况下获取列表中的所有迭代？

Question

I have set of tweets with 10 dictionaries in the list "tweets". Each dictionary has several tweets. The first tweet has 100 and the rest 9 have 15 each. I need the location of each tweet in all the dictionaries. When I try to iterate the values from a list it shows this error.

if (type(tweets[j]['statuses'][k]['place']['name'])) != None:

TypeError: 'NoneType' object is not subscriptable

The code I have used for the iteration is

for j in range (0,10):
    while j == 0:
       for k in range(0,100):
          st1 = tweets[j]['statuses'][k]['place']['name']
          print(st1)

I tried using "filter" to take out the "None" values, even that is not working. not every tweet has a location tagged to it. so it has None values. I need to print the locations of the tweets that are tagged.

Answer 1

Have you tried to check if the 'place' key is first available. I can see from your code that you are checking for ['place']['name']

Can you test your logic with the following filter logic without ['name']:

...
if (isinstance(tweets[j].get('statuses',[])[k].get('place', {}))) == dict:
...

Answer 2

The twitter api returns json, which is a dictionary type in Python. When you are calling keys using dict[key] syntax, this is called subscripting . Now, nested calls on a dict object are dependent on that object being a dictionary type:

dict[a][b] relies on dict[a] being a dictionary with key b being available. If dict[a] is a different type, say None or int , it is not subscriptable. This means that there is not necessarily a get attribute for that type. A simple way to fix this would be the following:

check = tweets[j]['statuses'][k]['place']

if isinstance(check, dict):
    # do things

This makes sure that check is of type dict and therefore can be subscripted with a key

EDIT: Note that using dict[key] syntax is not safe against KeyErrors . If you want to avoid those, use get :

my_dictionary = {'a': 1, 'b': 2}
my_dictionary['c']     # Raises KeyError: 'c' not in dictionary
my_dictionary.get('c') # returns None, no KeyError

It takes the form dict.get(key, <return_value>) , where return_value defaults to None

To make your program a bit more readable and avoid the inevitable infinite loop, ditch the while loop:

# This will get individual tweets
for tweet in tweets:

    # Returns all statuses or empty list
    statuses = tweet.get('statuses', [])
    for status in statuses:
        if not isinstance(status, dict):
            continue # will jump to next iteration of inner for loop

        # Will be a name or None, if empty dict is returned from place
        name = status.get('place', {}).get('name')
        if name:
            print(name)

Answer 3

for element in tweets:
    for s in element.get('statuses'):
       place = s.get('place')
       print(place['name'])

This fixed it.