PythonのBankAccount、間違った結果が得られました

私はこれらの行をPythonでコーディングしようとしています。

class BankAccount:
    def __init__(self, initial_balance):
        """Creates an account with the given balance."""
        …
    def deposit(self, amount):
        """Deposits the amount into the account."""
        …
    def withdraw(self, amount):
        """
        Withdraws the amount from the account.  Each withdrawal resulting in a
        negative balance also deducts a penalty fee of 5 dollars from the balance.
        """
        …
    def get_balance(self):
        """Returns the current balance in the account."""
        …
    def get_fees(self):
        """Returns the total fees ever deducted from the account."""
    …

「入金方法と引き出し方法はそれぞれ口座残高を変更します。引き出し方法（手数料を除く）でマイナスの残高が発生した場合、引き出し方法でも残高から5ドルの手数料が差し引かれます。get_feesメソッドもあるため、次のようになります。支払った料金を追跡するための変数を持つこと。

これがクラスの1つの可能なテストです。引き出しには5ドルの手数料がかかるため、それぞれ10と5の値を出力する必要があります。「」

しかし、私は間違った結果を得ました、最初は大丈夫ですが、2番目の結果は間違っていますアドバイスしてください
これは私のコードです

## python BankAccount program#################

fees = 0
class BankAccount:
        def __init__(self, init_bal):

        """Creates an account with the given balance."""
        self.init_bal = init_bal
        self.account = init_bal 
        self.fees = fees


    def deposit(self, amount):

        """Deposits the amount into the account."""
        self.amount = amount
        self.account += amount


    def withdraw(self, amount):

        """
        Withdraws the amount from the account.  Each withdrawal resulting in a
        negative balance also deducts a penalty fee of 5 dollars from the balance.
        """

        self.account -= amount
        if self.account < 0:
            self.account -= 5

        self.fees += 5




    def get_balance(self):

        """Returns the current balance in the account."""
        return self.account

    def get_fees(self):

        """Returns the total fees ever deducted from the account."""

        return self.fees


###### First account ###########################    
my_account_1 = BankAccount(10)
my_account_1.withdraw(15)
my_account_1.deposit(20)
my_account_1.withdraw(25)
print my_account_1.get_balance(), my_account_1.get_fees()
####### second account########################
my_account = BankAccount(10)
my_account.withdraw(5)
my_account.deposit(10)
my_account.withdraw(5)
my_account.withdraw(15)
my_account.deposit(20)
my_account.withdraw(5) 
my_account.deposit(10)
my_account.deposit(20)
my_account.withdraw(15)
my_account.deposit(30)
my_account.withdraw(10)
my_account.withdraw(15)
my_account.deposit(10)
my_account.withdraw(50) 
my_account.deposit(30)
my_account.withdraw(15)
my_account.deposit(10)
my_account.withdraw(5) 
my_account.deposit(20)
my_account.withdraw(15)
my_account.deposit(10)
my_account.deposit(30)
my_account.withdraw(25) 
my_account.withdraw(5)
my_account.deposit(10)
my_account.withdraw(15)
my_account.deposit(10)
my_account.withdraw(10) 
my_account.withdraw(15)
my_account.deposit(10)
my_account.deposit(30)
my_account.withdraw(25) 
my_account.withdraw(10)
my_account.deposit(20)
my_account.deposit(10)
my_account.withdraw(5) 
my_account.withdraw(15)
my_account.deposit(10)
my_account.withdraw(5) 
my_account.withdraw(15)
my_account.deposit(10)
my_account.withdraw(5) 
print my_account.get_balance(), my_account.get_fees()

the results are : -20 10 (first result)
                  -60 115 (second result)