我正在定义一个名为'car'的类我将它与一个在我的课上运行一系列测试的文档进行比较。但是，我收到了错误，我不知道为什么。这是我的代码。 Drive方法应该将汽车移动并将其移动指定的里程数。如果汽车可以用给定量的燃料达到所有里程，那么汽车就行驶并输出里程。如果它不能，它会达到它可以达到的最大里程数。 addFuel方法应该为汽车添加燃料，但是如果它溢出则不会添加任何燃料，如果指定的参数不是整数，或者不是正值，那么它应该是抛出一个例外。并且tripRange模块应该被赋予汽车中的加仑数量，并确定您将行驶多少英里。下面我先发布了我的代码，然后是代码来测试它。你能帮助我吗？我很感激。
#Define the class
class Car(object):
def __init__(self,fuelEfficiency=0,fuelCapacity=0,fuelLevel=0,odometer=0):
self.setCar(fuelEfficiency,fuelCapacity,fuelLevel,odometer)
def setFuelEfficiency(self,newFuelEfficiency):
self.setCar(fuelEfficiency = newFuelEfficiency)
def setFuelCapacity(self,newFuelCapacity):
self.setCar(fuelCapactity = newFuelCapacity)
def setFuelLevel(self,newFuelLevel):
self.setCar(fuelLevel = newFuelLevel)
def setOdometer(self,newOdometer):
self.setCar(odometer = newOdometer)
def setCar(self,fuelEfficiency = None,fuelCapacity = None,fuelLevel = None,odometer = None):
if fuelEfficiency == None:
fuelEfficiency = self.getFuelEfficiency
if fuelCapacity == None:
fuelCapacity = self.getFuelCapacity
if fuelLevel == None:
fuelLevel = self.getFuelLevel
if odometer == None:
odometer = self.getOdometer
self.fuelEfficiency = fuelEfficiency
self.fuelCapacity = fuelCapacity
self.fuelLevel = fuelLevel
self.odometer = odometer
def drive(self,miles):
if miles < 0:
return ("The car is not driven")
milesDriven = miles/self.fuelEfficiency
if milesDriven < self.fuelLevel:
print("The car drove {} miles".format(miles))
else:
if self.fuelLevel == 0:
print("The car drove 0 miles")
else:
newMiles = milesDriven * miles
print("The car drove {} miles".format(newMiles))
self.fuelLevel = self.fuelLevel - milesDriven
self.odometer += miles
def getCar(self):
#Returns a tuple that has (FE,FC,FL,OD)
return (self.fuelEfficiency,self.fuelCapacity,self.fuelLevel,self.odometer)
def addFuel(self,num):
if type(num) == str:
raise KeyError("String valued enter, an integer was expected.")
if num < 0:
print("Sorry, you need to enter a postive number.")
if num + self.fuelLevel > self.fuelCapacity:
return self.fuelLevel
else:
return self.fuelLevel + num
def getFuelEfficiency(self):
return self.getCar()[0]
def getFuelCapacity(self):
return self.getCar()[1]
def getFuelLevel(self):
return self.getCar()[2]
def getOdometer(self):
return self.getCar()[3]
def tripRange(self):
numOfMiles = self.fuelEfficiency
return numOfMiles
def __str__(self):
FE = self.getFuelEfficiency()
FC = self.getFuelCapacity()
FL = self.getFuelLevel()
OD = self.getOdometer()
string = '{}:{}:{}:{}'.format(FE,FC,FL,OD)
return string
这是测试代码：
from car import *
def checkCar(car, expected, message):
global errorsFound
mpg, cap, level, odo = expected
if car.getFuelEfficiency() != mpg:
errorsFound = True
print(message + ': Error efficiency. Expected ' + str(mpg))
print('\tCar:', car)
if car.getFuelCapacity() != cap:
errorsFound = True
print(message + ': Error capacity. Expected ' + str(cap))
print('\tCar:', car)
if car.getFuelLevel() != level:
errorsFound = True
print(message + ': Error level. Expected ' + str(level))
print('\tCar:', car)
if car.getOdometer() != odo:
errorsFound = True
print(message + ': Error odometer. Expected ' + str(odo))
print('\tCar:', car)
def checkNum(value, expected, message):
global errorsFound
if value != expected:
errorsFound = True
print(message + ': Error value. Expected {}. Got {}'.format(expected, value))
def main():
c = Car(25, 15)
checkNum(c.tripRange(), 0, 'Test 1')
expected = (25, 15, 0, 0)
checkCar(c, expected, 'Test 2')
c.addFuel(-1)
checkCar(c, expected, 'Test 3')
c.addFuel(1000)
checkCar(c, expected, 'Test 4')
c.addFuel('doctor')
checkCar(c, expected, 'Test 5')
c.addFuel(0)
checkCar(c, expected, 'Test 6')
c.addFuel(15)
expected = (25, 15, 15, 0)
checkCar(c, expected, 'Test 7')
c.drive(50)
expected = (25, 15, 13, 50)
checkCar(c, expected, 'Test 8')
c.drive(100000)
expected = (25, 15, 0, 375)
checkCar(c, expected, 'Test 9')
c.drive(5)
expected = (25, 15, 0, 375)
checkCar(c, expected, 'Test 10')
c.addFuel(10)
expected = (25, 15, 10, 375)
checkCar(c, expected, 'Test 11')
c.drive(-1)
expected = (25, 15, 10, 375)
checkCar(c, expected, 'Test 12')
c.drive(0)
expected = (25, 15, 10, 375)
checkCar(c, expected, 'Test 13')
checkNum(c.tripRange(), 250, 'Test 14')
if not errorsFound:
print('No Errors Found')
errorsFound = False
main()
答案 0 :(得分：1)
您的代码按预期工作。
尽管我在car.py文件中发现了一些缩进错误，这可能就是原因。特别是__init__对象的Car方法def__init__(..)，没有空格。
如果你在终端输出中讨论被抛出的异常：
Test 1: Error value. Expected 0. Got 25
Sorry, you need to enter a postive number.
Traceback (most recent call last):
File "/home/crispycret/Desktop/testcase.py", line 89, in <module>
main()
File "/home/crispycret/Desktop/testcase.py", line 42, in main
c.addFuel('doctor')
File "/home/crispycret/Desktop/car.py", line 64, in addFuel
raise KeyError("String valued enter, an integer was expected.")
KeyError: 'String valued enter, an integer was expected.'
[Finished in 0.1s with exit code 1]
这是可以预料的。至于第42行main() test.py函数中的原因，您尝试执行c.addFuel('doctor')，Car.addFuel()方法内部KeyError("String valued enter, an integer was expected.")输入的类型是一个字符串。
顺便提一下，在引发错误时应该使用适当的异常，在这种情况下，你应该使用TypeError("String valued enter, an integer was expected.")来表示变量类型是错误的。
答案 1 :(得分：1)
Python不是Java，所以不要像这样写。
通常不需要Getters和Setter，因此不要添加它们，如果需要，您可以随时轻松完成。也没有强制实例成员保护，但self._odometer中的下划线向读者发出_odometer是私有的信号。
放弃类型声明并接受鸭子打字。在addFuel()中，您检查参数是否为str类型，如果不是，则继续。但是，参数可以是file，module，dict，list等类型。你无法全部检查，所以最好不要尝试。
剩下的就是drive()被打破了，但现在显然是这样，因为已经删除了很多垃圾而且tripRange()是多余的。这留下了一种工作方法addFuel，很难用于测试两行简单的代码。
class Car(object):
def __init__(self, efficiency=0, capacity=0, fuel=0, odometer=0):
self.efficiency = efficiency
self.capacity = capacity
self.fuel = fuel
self.odometer = odometer
# four useless setters removed
def drive(self, miles):
# argument test removed
# miles / (miles / 1 gallon) = miles * (1 gallon / miles) = 1 gallon
# so this expression and thus method are broken
one_gallon = miles / self.efficiency
if one_gallon < self.fuel:
print("The car drove {} miles".format(miles))
elif self.fuel == 0:
print("The car drove 0 miles")
else:
newMiles = milesDriven * miles
print("The car drove {} miles".format(newMiles))
self.fuel -= one_gallon
self.odometer += miles
def addFuel(self, volume):
# Even more argument tests removed.
if volume + self.fuel <= self.capacity:
self.fuel += volume
# The method "tripRange()" is equivalent to "car.efficiency" so is removed
def __str__(self):
# trivial getters don't exist; the format template is now conventional
return '<Car {}, {}, {}, {}>'.format(self.efficiency, self.capacity,
self.fuel, self.odometer)
你的测试中出现错误可能是因为2/3的方法被破坏了，甚至没有考虑到特殊的getCar()和所有琐碎的制定者和吸气剂。你需要编写的代码少于你的代码。