Is there a way to split a DF using column name comparison? - python-3.x

Question

I am extremely new to Python. I've created a DataFrame using a csv file. My file is a complex nested json file having header values at the lowest granular level.
[Example] df.columns = [ID1, fullID2, total.count, total.value, seedValue.id, seedValue.value1, seedValue.value2, seedValue.largeFile.id, seedValue.largeFile.value1, seedValue.largeFile.value2......]
Requirement: I have to create multiple smaller csvs using each of the columns that are granular and ID1, fullID2.
My approach that I figured is: save the smaller slices by splitting on the header value.
Problem 1: Not able to split the value correctly or traverse to the first location for comparison.
[Example]
I'm using df.columns.str.split('.').tolist(). Suppose I get the below listed value, I want to compare seedValue of id with seedValue of value1 and pull out this entire part as a new df.
{['seedValue','id'],['seedValue'.'value1'], ['seedValue'.'value2']}
Problem 2: Adding ID1 and fullID2 to this new df.
Any help or direction to achieve this would be super helpful !
[Final output]
df.columns = [ID1, fullID2, total.count, total.value, seedValue.id, seedValue.value1, seedValue.value2, seedValue.largeFile.id, seedValue.largeFile.value1, seedValue.largeFile.value2......]
post-processing the file -
seedValue.columns = ID1,fullID2,id,value1,value2
total.columns = ID1,fullID2,count,value
seedValue.largeFile.columns = ID1,fullID2,id,value1,value2

Answer 1

While I do not possess your complex data to provide a more particular solution. I was able to reproduce a similar case with a .csv sample data, which will exemplify how to achieve what you aim with your data.
In order to save in each ID in a different file, we need to loop through the ID's. Also, assuming there might be more duplicate ID's, the script will save each group of ID's into a .csv file. Below is the script, already with sample data:
import pandas as pd
import csv
my_dict = { 'ids' : [11,11,33,55,55],
'info' : ["comment_1","comment_2", "comment_3", "comment_4", "comment_5"],
'other_column': ["something", "something", "something", "", "something"]}
#Creating a dataframe from the .csv file
df = pd.DataFrame(my_dict)
#sorting the value
df = df.sort_values('ids')
#g=df.groupby('ids')
df
#looping through each group of ids and saving them into a file
for id,g in df.groupby('ids'):
g.to_csv('id_{}.csv'.format(id),index=False)#, header=True, index_label=False)
And the output,
id_11.csv
id_33.csv
id_55.csv
For instance, within id_11.csv:
ids info other_column
11 comment_1 something
11 comment_2 something
Notice that, we use the field ids in the name of each file. Moreover, index=False which means that a new column with indexes for each line of data won't be created.
ADDITIONAL INFO: I have used the Notebook in AI Platform within GCP to execute and test the code.

Answer 2

Compared to the more widely known pd.read_csv, pandas offers more granular json support through pd.json_normalize, which allows you to specify how to unnest the data, which meta-data to use, etc.
Apart from this, reading nested fields from a csv into a two-dimensional dataframe might not be the ideal solution here, and having nested objects inside a dataframe can often be tricky to work with.
Try to read the file as a pure dictionary or list of dictionaries. You can then loop through the keys and create a custom logic to check how many more levels you want to go down, how to return the values and so on. Once you are on a lower level and prefer to have this inside of a dataframe, create a new temporary dataframe, then append these parts together inside the loop.