TypeError：选择行数据框熊猫的子集时需要一个整数

Question

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  'country': 'Australia',
  'country_code': 'AUS',
  'full_name': 'Melbourne, V',
  'id': 'c4f1830ea4b8caaf',
  'name': 'Melbourne',
  'place_type': 'city',
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I have a json file which contains a list of json objects (each has the structure like above)

So I read it into a dataframe:

df = pd.read_json('data.json')

and then I try to get all the rows which are the 'city' type by:

df = df[df['place']['place_type'] == 'city']

but then I got the 'TypeError: an integer is required' During handling of the above exception, another exception occurred: KeyError: 'place_type'

Then I tried:

df['place'].head(3)
=>
0    {'id': '01864a8a64df9dc4', 'url': 'https://api...
1    {'id': '01864a8a64df9dc4', 'url': 'https://api...
2    {'id': '0118c71c0ed41109', 'url': 'https://api...
Name: place, dtype: object

So df['place'] return a series where keys are the indexes and that's why I got the TypeError

I've also tried to select the place_type of the first row and it works just fine:

df.iloc[0]['place']['place_type']
=>
city

The question is how can I filter out the rows in this case?

Solution:

Okay, so the problem lies in the fact that the pd.read_json cannot deal with nested JSON structure, so what I have done is to normalize the json object:

with open('data.json') as jsonfile:
    data = json.load(jsonfile)

df = pd.io.json.json_normalize(data)

df = df[df['place.place_type'] == 'city']

Answer 1

You can use the a list comprehension to do the filtering you need.

df = [loc for loc in df if d['place']['place_type'] == 'city']

This will give you an array where the elements place_type is 'city' .

Answer 2

I don't know if you have to use the place_type that is the index, to show all the rows that contains city.

"and then I try to get all the rows which are the city type by:"

This way you can get all the rows that contains city in the column place :

df = df[(df['place'] == 'city')]