1. There are 10,000 yuan on hand when keeping accounts. 2. You can record the money spent, the money saved, and the income and expenditure details

import pickle
import os
import time


def cost(wallet, record): # record the function of spending money
    amount = int(input('amount:'))
    comment = input('comment:')
    date = time.strftime('%Y-%m-%d')
    with open(wallet,'rb') as fobj:
        balance = pickle.load(fobj)-amount
    with open(wallet,'wb') as fobj:
        pickle.dump(balance, fobj)
    with open(record,'a') as fobj:
        fobj.write(
            '%-12s%-8s%-8s%-10s%-20s\n'% (date, amount,'', balance, comment)
        )

def save(wallet, record): # Record the function of saving money
    amount = int(input('amount:'))
    comment = input('comment:')
    date = time.strftime('%Y-%m-%d')
    with open(wallet,'rb') as fobj:
        balance = pickle.load(fobj) + amount
    with open(wallet,'wb') as fobj:
        pickle.dump(balance, fobj)
    with open(record,'a') as fobj:
        fobj.write(
            '%-12s%-8s%-8s%-10s%-20s\n'% (date,'', amount, balance, comment)
        )

def query(wallet, record): # Function for querying revenue and expenditure details
    print('%-12s%-8s%-8s%-10s%-20s'% ('date','cost','save','balace','comment'))
    with open(record) as fobj:
        for line in fobj:
            print(line, end='')
    with open(wallet,'rb') as fobj:
        balance = pickle.load(fobj)
    print("Latest Balance: %d"% balance)


def show_menu():
    cmds = {'0': cost, '1': save, '2': query}
    prompt = """(0) cost
(1) save
(2) query
(3) exit
Please input your choice(0/1/2/3): """
    wallet ='wallet.data'
    record ='record.txt'
    if not os.path.exists(wallet):
        with open(wallet,'wb') as fobj:
            pickle.dump(10000, fobj)

    while True:
        try:
            choice = input(prompt).strip()[0]
        except IndexError:
            continue
        except (KeyboardInterrupt, EOFError):
            print()
            choice = '3'

        if choice not in '0123':
            print('Invalid input. Try again.')
            continue

        if choice == '3':
            break
        cmds[choice](wallet, record)

if __name__ =='__main__':
    show_menu()