Data not appending in dataset through python - outside dss

[nadardin]

Hi,

I am trying to append the data in my current dataset.

Tried with all method (write_row_dict, write_tuple, write_dataframe).

While executing its shows 1 rows successfully written, but when I go and check dataiku application and check dataset only one row available.

Can any one guide on this ? how to resolve this ?

Thanks,

[AlexandreV]

Hi @nadardin,

could you share the code you tried to run?

What error did you get?

Alex

[nadardin]

I am trying to append data in input data set. Can we append in input data set

data = {'xx:'xxx','key':'1212'}

df = pandas.DataFrame(pandas.json_normalize([data]);

writer = dataiku.core.Dataset(dataSetName,projectKey);

vp = dataiku.core.dataset_write.DatasetWriter(writer);

vp.write_dataframe(df);

No Error. It's showing 1 rows successfully written

Thanks

[AlexandreV]

Hello,
you could get your output dataset as a dataframe and append the new data to it.

import dataiku
import pandas as pd

output_dataset = dataiku.Dataset("out")
out_df = output_dataset.get_dataframe()

data = [
    {'xx':'row 1','key':'1212'},
    {'xx':'row 2','key':'1212'},
]
df_to_append = pd.json_normalize(data)

with out_df.get_writer() as writer:
    writer.write_dataframe(out_df.append(df_to_append))

Hope this solves your issue

Alex

[AndrewM]

Hello,

If you're using a Python Recipe in the flow you may want to try setting the output dataset to 'Append instead of overwrite' under 'Inputs/Outputs'. This will add new rows to the output dataset every time the recipe is run instead of overwriting the data. 

You can also use a Pandas data frame append mode in your Python code to append data: https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.append.html. Since we can directly write a dataframe to a dataset in DSS, we can append the new rows to the dataframe in the Python code and then write that dataframe to the dataset. I've included a small sample below that illustrates this. It takes a dataset (test_csv_df) and then appends it to itself in a separate dataframe. The appended data dataframe is then written back to another dataset in DSS.

# -*- coding: utf-8 -*-
import dataiku
import pandas as pd, numpy as np
from dataiku import pandasutils as pdu

# Read recipe inputs
test_csv = dataiku.Dataset("Test-csv")
test_csv_df = test_csv.get_dataframe()

temp_df = test_csv_df.append(test_csv_df) 

# Write recipe outputs
temp_df = dataiku.Dataset("collapsed-data")
temp_df.write_with_schema(collapsed_data_df)

Hope this helps!

Andrew M