Python class 030315 | Python Fiddle

class OverdrawnError(Exception):
    pass

class Account(object):
    __slot__=['name','balance','trans']
    num_acs = 0
    
    
    @staticmethod                   #technical term - decorator (annotation)
    def get_num_acs():
        return Account.num_acs
    	#get_num_acs = staticmethod(get_num_acs)
    
	def __init__(self, name):
        self.name = name
        self.balance = 0
        self.trans = list()
        Account.num_acs += 1
        # self._dict_['name'] = name
        # self._dict_['balance'] = 0
        
	def __getitem__(self, index):
    	pass
        #return self.trans[index]
    
    def __iter__(self):
        return iter(self.trans)
        
	def get_all_trans(self):
        return tuple(self.trans)
        
    def get_balance(self):
        return self.balance
    
    def deposit(self, amount):
        self.trans.append(amount)
        self.balance += amount
        
    def withdraw(self, amount):
        self.trans.append(-amount)
    	self.balance -= amount
         
                
def self_tests():    
    b1 = Account('joe')   # rv = Account.__new__(...)	
                          # Account.__init__(rv,'joe')
        
    
    assert(b1.get_balance() ==0)    #b1.__class__.get_balance(b1)
    
    b1.deposit(100)
    assert(b1.get_balance() == 100)
    
    b1.withdraw(10)
    assert(b1.get_balance() == 90)
    
    assert (b1 !=None)
    
    
    #print b1.get_num_acs()
    
    assert(b1.get_num_acs() ==1)
    assert(Account.get_num_acs() ==1) #Account.get_num_acs()
    
    
    assert(b1.get_all_trans() == [100.-10])
    
    print b1.get_all_trans()[-2 :]
    
    import pdb
    pdb.set_trace()
    
    
    assert( b1[0] == 100)    #b1.__class__.__getitem__(b1,0)
    print b1[0:2]
    
    for transaction in b1:
        print transaction
    
    list(b1)
    tuple(b1)
    
    
    b1.balance = 1000000000000000000
    print b1.get_balance()
    
    print b1.balance
    
    
    
    
    
    print'ALL TESTS PASSED'

if __name__ =='__main__':
    self_tests()

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