#0101

Inner Join Users and Events

EasyPandas15 min10 XP

Problem

Given users and events DataFrames, return an inner join on user_id sorted by event_id.

Why This Matters

Joining tables correctly is one of the most common data-analysis tasks.

Function Signature

def join_known_user_events(users, events):

Examples

Example 1

Inputevents include user 99 not in users

Outputevent for user 99 removed

Inner join keeps only matching user ids.

Constraints

Return the exact structure requested.
Handle the edge cases mentioned in the prompt.
Prefer clear logic over clever one-liners.

CodePython

import pandas as pd

def join_known_user_events(users, events):
    """
    Input example: events include user 99 not in users
    Return: event for user 99 removed
    Return the value from the function so the tests can compare it. Do not print unless the prompt asks.
    """
    # write your code here
    return events

import pandas as pd

def join_known_user_events(users, events):
    """
    Input example: events include user 99 not in users
    Return: event for user 99 removed
    Return the value from the function so the tests can compare it. Do not print unless the prompt asks.
    """
    # write your code here
    return events

Visible browser tests run here when available.

Testcases1 visible / 3 hidden categories

Core example

Inputevents include user 99 not in users

Expectedevent for user 99 removed

Inner join keeps only matching user ids.

Hidden Test Categories

all users knownno users knownmultiple events per user