Python DataFrame Duplicate Removal | Dataford Interview Questions

Given a dataframe, how would you identify and remove duplicates based on multiple conditional rules and move them to a separate dataframe?

Represent the dataframe as a list of dictionaries and return (retained, duplicates), preserving input order within both outputs. For rows with mode="exact", duplicates share entity_id, day, and value; for rows with mode="grouped", duplicates share only entity_id and day. Keep the first row for each conditional key and move later matches to the duplicate output.

Constraints

1 <= len(rows) <= 100000
Each row contains entity_id, day, mode, and value
mode is either exact or grouped
Keep the first occurrence of every conditional key
Preserve input order in both returned lists

Function Signature

def separate_duplicates(rows):

Your question is Python DataFrame Duplicate Removal. Start with the requirements in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.

Problem

Given a dataframe, how would you identify and remove duplicates based on multiple conditional rules and move them to a separate dataframe?

Constraints

1 <= len(rows) <= 100000
Each row contains entity_id, day, mode, and value
mode is either exact or grouped
Keep the first occurrence of every conditional key
Preserve input order in both returned lists

Function Signature

def separate_duplicates(rows):

Your question is Python DataFrame Duplicate Removal. Start with the requirements in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.