#0155

Keep Latest Record per Entity

MediumPandas25 min20 XP

Problem

Given rows with id, updated_at, and value, return the latest row for each id sorted by id.

Why This Matters

Latest-record logic shows up in user profiles, slowly changing dimensions, model features, and event snapshots.

Function Signature

def latest_records(df):

Examples

Example 1

Inputid 1 appears on Jan 1 and Jan 3; id 2 appears on Jan 2

Outputid 1 keeps Jan 3; id 2 keeps Jan 2

Sorting by updated_at makes keep="last" choose the newest row per id.

Constraints

Return the exact requested value.
Handle empty or small inputs when the prompt allows them.
Keep the code readable and deterministic.

CodePython

import pandas as pd

def latest_records(df):
    """
    Input example: id 1 appears on Jan 1 and Jan 3; id 2 appears on Jan 2
    Return: id 1 keeps Jan 3; id 2 keeps Jan 2
    Return the value from the function so the tests can compare it. Do not print unless the prompt asks.
    """
    # write your code here
    return df

import pandas as pd

def latest_records(df):
    """
    Input example: id 1 appears on Jan 1 and Jan 3; id 2 appears on Jan 2
    Return: id 1 keeps Jan 3; id 2 keeps Jan 2
    Return the value from the function so the tests can compare it. Do not print unless the prompt asks.
    """
    # write your code here
    return df

Visible browser tests run here when available.

Testcases1 visible / 3 hidden categories

Core example

Inputid 1 appears on Jan 1 and Jan 3; id 2 appears on Jan 2

Expectedid 1 keeps Jan 3; id 2 keeps Jan 2

Sorting by updated_at makes keep="last" choose the newest row per id.

Hidden Test Categories

empty or smallest inputduplicates or repeated valueslarger realistic input