import datetime

class Journal:  
    def __init__(self, journal_name):  
        self.journal_name = journal_name  
        self.journal_date = datetime.datetime.now().strftime('%Y-%m-%d')  
        self.journal_ expenses = []  
      
    def add_expense(self, amount, category):  
        if category not in ['正餐', '零食', '玩樂', '應酬', '學習']:  
            raise ValueError('Invalid category')  
        self.journal_expenses.append((category, amount))  
          
    def remove_expense(self, category):  
        self.journal_expenses.remove((category, self.journal_expenses.index(category) + 1))  
          
    def list_expenses(self):  
        if not self.journal_expenses:  
            return []  
        expenses = []  
        for category, index in self.journal_expenses:  
            expenses.append({'category': category, 'amount': self.journal_expenses[index]})  
        return expenses  
      
    def save_journal(self, filename):  
        with open(filename, 'w') as f:  
            f.write(f'Date: {self.journal_date}\n')  
            f.write(f'Expenses:\n')  
            for category, index in self.journal_expenses:  
                f.write(f'{category}: {self.journal_expenses[index]}\n')  
            f.write(f'\n')

if __name__ == '__main__':  
    journal = Journal('Expense Journal')  
      
    while True:  
        print('Journal>')  
        choice = input('Enter an option (add, remove, list, save): ')  
          
        if choice == 'add':  
            category, amount = input('Enter category: ').split(',')  
            if not category or not amount:  
                print('Invalid input')  
                continue  
            journal.add_expense(amount, category)  
        elif choice == 'remove':  
            category = input('Enter category: ').split(',')[0]  
            journal.remove_expense(category)  
        elif choice == 'list':  
            journal.list_expenses()  
        elif choice == 'save':  
            filename = input('Enter filename: ')  
            journal.save_journal(filename)  
        else:  
            print('Invalid choice')  

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