class Battery():
"""一次模拟电动汽车电瓶的简单尝试"""
def __init__(self, battery_size=60):
"""初始化电瓶的属性"""
self.battery_size = battery_size
def describe_battery(self):
"""打印一条描述电瓶容量的消息"""
print("This car has a " + str(self.battery_size) + "-kWh battery.")
def get_range(self):
"""打印一条描述电瓶续航里程的消息"""
if self.battery_size == 70:
range = 240
elif self.battery_size == 85:
range = 270
message = "This car can go approximately " + str(self.range)
message += " miles on a full charge."
print(message)
由于 battery_size 已被赋值，且不满足 get_range方法中的条件测试，所以没有起到修改 range 的作用；
试着修改代码：
class Battery():
"""一次模拟电动汽车电瓶的简单尝试"""
def __init__(self, battery_size=60, range=''):
"""初始化电瓶的属性"""
self.battery_size = battery_size
self.range = range
def describe_battery(self):
"""打印一条描述电瓶容量的消息"""
print("This car has a " + str(self.battery_size) + "-kWh battery.")
def get_range(self):
"""打印一条描述电瓶续航里程的消息"""
if self.battery_size == 70:
self.range = 240
elif self.battery_size == 85:
self.range = 270
else:
self.range = 210
message = "This car can go approximately " + str(self.range)
message += " miles on a full charge."
print(message)
