Wallet Balances After Transfers

PandasMediumMid level~10 min

Problem

You are given two DataFrames:
- `wallets` with `wallet_id`, `holder`, `opening` (the starting balance)
- `transfers` with `transfer_id`, `sender_id`, `receiver_id`, `amount`, `sent_on`

Each transfer moves `amount` out of the sender's wallet and into the receiver's wallet. For every wallet compute its final `balance = opening + (total received) - (total sent)`. A wallet that sent or received nothing keeps its opening balance.

Return columns `wallet_id`, `holder`, `balance`, and `overdrawn`, where `overdrawn` is `'Yes'` when the final balance is negative and `'No'` otherwise. Every wallet appears in the output.

Input data

Example rows — the live problem includes the full dataset.

wallets

wallet_id	holder	opening
1	Mireille	100
2	Tariq	200
3	Sven	10000
4	Liwei	800

transfers

transfer_id	sender_id	receiver_id	amount	sent_on
1	1	3	400	2021-08-01
2	3	2	500	2021-08-02
3	2	1	200	2021-08-03

Expected output

Your answer should return 4 rows with the columns wallet_id, holder, balance, overdrawn.

Starter code (Pandas (Python))

import pandas as pd

def wallet_balances_after_transfers(wallets, transfers) -> pd.DataFrame:
    # Your code here
    return wallets

Solve this Pandas question free

Write Pandas (Python) and run it instantly in your browser — even on your phone. No signup needed to try.

Solve it now → Create free account

Solution & explanation

Create a free account to unlock the optimal solution, a step-by-step explanation, and the hidden test cases that grade your answer.