Per below pdn link, Reporting or Exporting of Propositions by pyIssue and/or pyGroup is an enhancement request.

https://community.pega.com/support/support-articles/export-propositions-pyissue-and-pygroup

I did a search and found out the following old solution (Using Excel Template  and MSOGenerateExcel activity(XLSX)) . You can give a try. 

You can use existing OOTB activity @baseclass.MSOGenerateExcelFile available in PRPC to generate excel spreadsheet in .xlsx format. 

 

Create a template file (propositiontypetemplate.xlsx) with all the required fields. In this template hard code header names and provide placeholder tokens {.pyPropositions().pyCategory input}

for populating the data.

See screenshot #1 "propositiontypetemplate".

Upload this file as binary file under Technical category to create RULE-FILE-BINARY rule. Create a button on the data grid and call activity @baseclass.MSOGenerateExcelFile.

Pass following parameters.

FSFileName       :  "PropositionDetails.xlsx"

TemplateRFB    : "excel!propositiontypetemplate!xlsx"

DownloadFile   :  checked

See screenshot #2 "Sample-output". 

Benefits of this approach 

·        Output is an XLSX file , which is more structured. Hence reading and exporting such a file is much easier

·        Easy to implement as the activity is already available in PRPC

·        Any change in data grid will only need to change in template. No code changes required

·        Template can be designed by the user as required

Limitations of this approach 

·        Because template is a static file it cannot be modified automatically when attributes are added. Hence it does not support dynamic updates in data grid structure attribute list.

·        Because of dependency on baseclass, if there is any change in MSOGenerateExcel , it would need to relook at this implementation.

·      Because it is a XLSX file it can be openned only in MS Excel 2007 and above. Older versions are not compatible.