[QST] How to use cudf.Series() and get_json_object()

[zlwu92]

Does the API get_json_object() described in https://docs.rapids.ai/api/cudf/legacy/api_docs/api/cudf.core.column.string.stringmethods.get_json_object/
supports the json query?

I installed rapids cudf libraries via conda following the instructions in rapids site.

Follow the example in the above link, I write python code like below

But it gives an error like this? What is the problem?

[davidwendt]

The str.get_json_object() only works on strings column data. The s object in your example is created as a struct type.

>>> s = cudf.Series({"employee": {"name": "sonoo", "salary": 56000, "married": "true"}})
>>> print(s)
employee    {'married': 'true', 'name': 'sonoo', 'salary':...
dtype: struct

You can use the struct.field() function to access the name as follows:

>>> s.struct.field('name')
employee    sonoo
dtype: object

Reference: https://docs.rapids.ai/api/cudf/legacy/api_docs/api/cudf.core.column.struct.structmethods.field/#cudf.core.column.struct.StructMethods.field

Hopefully that helps.

[zlwu92]

The str.get_json_object() only works on strings column data. The s object in your example is created as a struct type.

>>> s = cudf.Series({"employee": {"name": "sonoo", "salary": 56000, "married": "true"}})
>>> print(s)
employee    {'married': 'true', 'name': 'sonoo', 'salary':...
dtype: struct

You can use the struct.field() function to access the name as follows:

>>> s.struct.field('name')
employee    sonoo
dtype: object

Reference: https://docs.rapids.ai/api/cudf/legacy/api_docs/api/cudf.core.column.struct.structmethods.field/#cudf.core.column.struct.StructMethods.field

Hopefully that helps.

[zlwu92]

Ok. Thank you. Can you share me a simple example created as a strings column data object?
Actually I got error in the example provided in https://docs.rapids.ai/api/cudf/legacy/api_docs/api/cudf.core.column.string.stringmethods.get_json_object/

[davidwendt]

The doc is a bit confusing since the formatter would have issues with the three double-quotes """.
Here is the example perhaps in a better format:

>>> s = cudf.Series([ """ {
... "store":{ "book":[
...   { "category":"reference",
...     "author":"Nigel Rees",
...     "title":"Sayings of the Century",
...     "price":8.95 },
...   { "category":"fiction",
...     "author":"Evelyn Waugh",
...     "title":"Sword of Honour",
...     "price":12.99 }
... ] } } """ ])
>>> s
0     {\n"store":{ "book":[\n  { "category":"refere...
dtype: object
>>> s.str.get_json_object("$.store.book")
0    [\n  { "category":"reference",\n    "author":"...
dtype: object
>>> s.str.get_json_object("$.store.book[0].author")
0    Nigel Rees
dtype: object