Read all the pages of a JSON file

[sebastienH]

Hello,

I would like to read a JSON file. But with the URL I only access to the first page (the file is paginated). I would like to read ALL the pages.

With Talend I do a loop, but whith JSON I don't know. Can I get help ?

Thank you very much

[ATsao · Accepted solution]

Hi Sebastien,

By default, recipes will run in "overwrite" mode in DSS. In your python recipe, try navigating to the Inputs/Outputs tab and select the Append instead of overwrite option. 

This should allow the results to be appended instead of overwritten in your output dataset. I hope that this helps!

Thanks again,

Andrew

[ATsao]

Hi Sebastien,

Could you provide more details about this JSON file and where it's located? Are you using a download recipe or how are you trying to ingest this data into your Flow in DSS? 

Thanks,

Andrew

[sebastienH]

Hello,

Thank you for your answer.

I get the JSON by URL https://porta....

I can only give the end of the url :

e5e3&query_id=735&offset=0    for the first page

e5e3&query_id=735&offset=1    for the second page

etc. There are thousands pages.

I tried a download recipe, but I can’t use « add another source » for each page. Too many pages.

Is it possible to do a loop ?

Thank you

[ATsao]

Hi Sebastien,

Your best bet might be to create your own code recipe, such as python, where you could handle iterating through the different pages to read in the necessary data, create your own dataframe, and then write this dataframe as an output into a dataset in DSS. 

Best,

Andrew

[sebastienH]

Hi Andrew,

Thank you for your answer. I will use a python recipe without input. I thought that an input was necessary, but it's not.

Thank you,

Best,

Sebastien

[ATsao]

Hi Sebastien,

That's correct. For code recipes, only an output is necessary (even if it's a dummy output). 

Thanks,

Andrew

[sebastienH]

Hi Andrew,

I forgot to "accept as solution", but I may have a last question.

Here is my code :

for i in range(5):
url = "https://portail.....................35&offset={0}".format(i)
fileA= pd.read_json(url, orient='records')
loop_issues1.write_from_dataframe(fileA)

The problem is that It replaces everything at each loop. But I want it to add data.

I tried to tell it "mode="a"",but it doesn't understand.

Thank you for your help. I did'nt find nothing about write_from_dataframe on pandas.pydata.org

[ATsao · Accepted solution]

Hi Sebastien,

By default, recipes will run in "overwrite" mode in DSS. In your python recipe, try navigating to the Inputs/Outputs tab and select the Append instead of overwrite option. 

This should allow the results to be appended instead of overwritten in your output dataset. I hope that this helps!

Thanks again,

Andrew

[sebastienH · Accepted solution]

Hi,

I did not see that !! Thank you ! Problem solved

Sebastien