萌新求大佬帮忙！！python问题！！

[刚刚接触java]

我是一步步按照书写的，原代码如下：

class Car():
"""该程序主要用于一次模拟汽车的简单尝试"""

def __init__(self, make, model, year):
"""初始化描述汽车的属性"""
self.make = make
self.model = model
self.year = year
self.odometer_reading = 0

def get_descriptive_name(self):
"""返回整洁的描述性名称"""
long_name = f"{self.year} {self.make} {self.model}"
return long_time.title()

def road_odometer(self):
"""打印出一条信息，指出汽车的里程"""
print(f"This car has {self.odometer_reading} miles on it.")

def update_odometer(self, mileage):
"""
将里程表读数设置为指定的值，
并拒绝将里程表往回调。
"""
if mileage >= self.odometer_reading:
self.odometer_reading = mileage
else:
print("You can't roll back an odometer!")

def increment_odometer(self, miles):
"""将里程表读数增加指定的量"""
self.odometer_reading += miles

my_new_car=Car('audi','a4',2019)
print (my_new_car.get_descriptive_name())

pycharm和jupter的错误显示：
NameError Traceback (most recent call last)
<ipython-input-8-abd31ead77cc> in <module>
2
3 my_new_car=Car('audi','a4',2019)
----> 4 print (my_new_car.get_descriptive_name())
5

~\Desktop\大数据\第二周 类\car.py in get_descriptive_name(self)
11 """打印出一条信息，指出汽车的里程"""
12 print(f"This car has {self.odometer_reading} miles on it.")
---> 13
14 def update_odometer(self, mileage):
15 """

NameError: name 'long_time' is not defined

我换成long_name = "{} {} {}".format(self.year, self.make, self.model)还是不行。。
求大佬救命！！

[罗卜基斯]

def get_descriptive_name(self): ... """返回整洁的描述性名称""" ... long_name = f"{self.year} {self.make} {self.model}" ... return long_name.title()