导出为 Python 中的文本
Exporting to text in Python
如果用户 select 选择了该选项，我的部分任务是导出为文本。除了那一部分，我似乎什么都对。谁能建议我哪里出错了？我是否需要在代码中的其他地方添加一些东西才能正常工作？当我 select 选项 6 时，我收到 automobilelist 未定义的错误。
class Automobile:
# constructor, it takes parameters make, model, year and mileage
def __init__(self,aMake,aModel,aColor,aYear,aMileage):
# assign passed values to instance variables
self.setMake(aMake) # string
self.setModel(aModel) # string
self.setColor(aColor) # string
self.setYear(aYear) # int
self.setMileage(aMileage) # int
# setter of make
# it takes 1 parameter make
# it doesn't returns anything
def setMake(self, aMake):
self.__make = aMake
# getter of make
# it doesn't take any parameters
# it returns make
def getMake(self):
return self.__make
# setter of model
# it takes 1 parameter model
# it doesn't returns anything
def setModel(self, aModel):
self.__model = aModel
# getter of model
# it doesn't take any parameters
# it returns model
def getModel(self):
return self.__model
# setter of color
# it takes 1 parameter color
# it doesn't returns anything
def setColor(self, aColor):
self.__color = aColor
return True
# getter of color
# it doesn't take any parameters
# it returns color
def getColor(self):
return self.__color
# setter of year
# it takes 1 parameter year
# it doesn't returns anything
def setYear(self, aYear):
self.__year = aYear
# getter of year
# it doesn't take any parameters
# it returns year
def getYear(self):
return self.__year
# setter of mileage
# it takes 1 parameter year
# it doesn't returns anything
def setMileage(self, aMileage):
self.__mileage = aMileage
# getter of mileage
# it doesn't take any parameters
# it returns mileage
def getMileage(self):
return self.__mileage
# string representation of the instance variables
# it doesn't take any parameters
# it returns string form of object
def __str__(self):
return "{}, {}, {}, {}, {}".format(self.getMake(),self.getModel(),self.getColor(),self.getYear(),self.getMileage())
class Automobiledealership:
# constructor
# it initializes the empty automobile list
def __init__(self):
self.__automobilelist = []
# adds automobile to dealership
# it takes automobile class object as parameter
# it doesn't returns anything
def addAutomobile(self, automobile):
self.__automobilelist.append(automobile)
# removes automobile from dealership
# it takes index of automobile in the list as parameter
# it doesn't returns anything
def removeAutomobile(self, index):
del self.__automobilelist[index-1]
# returns automobile from dealership
# it takes index of automobile in the list as parameter
# it returns automobile object located at that index
def getAutomobile(self, index):
return self.__automobilelist[index-1]
# prints the list of automobiles
# it doesn't take any parameters
# it doesn't returns anything
def printAutomobileList(self):
if len(self.__automobilelist)==0:
print("No automobiles in dealership")
else:
for i in range(len(self.__automobilelist)):
print("{}. {}".format(i+1,self.__automobilelist[i]))
# add some automobiles to the dealership for Sample Inventory
def addSampleAutomobiles(automobiles):
automobiles.addAutomobile(Automobile("Ford", "Focus", "Red", 2019, 8000))
automobiles.addAutomobile(Automobile("Toyota","Corolla","White",2007,65000))
automobiles.addAutomobile(Automobile("Ford","Endura","Black",2019,5000))
automobiles.addAutomobile(Automobile("Audio","A1","White",2016,23000))
automobiles.addAutomobile(Automobile("Toyota", "Camry", "Red", 2000, 25000))
automobiles.addAutomobile(Automobile("Ford","Everest","Black",2017,16000))
automobiles.addAutomobile(Automobile("Mazda","MX5","Red",2015,33000))
automobiles.addAutomobile(Automobile("Ford","Escape","Grey",2018,15000))
automobiles.addAutomobile(Automobile("Toyota", "Prius", "Red", 2010, 35000))
def addAutomobile(automobiles):
make = input("Please enter Make >> ")
model = input("Please enter Model >> ")
color = input("Please enter Color >> ")
year = int(input("Please enter Year >> "))
mileage = int(input("Please enter Mileage >> "))
automobiles.addAutomobile(Automobile(make,model,color,year,mileage))
def removeAutomobile(automobiles):
index = int(input("Please enter number of the automobile to be removed >> "))
automobiles.removeAutomobile(index)
def updateAutomobile(automobiles):
index = int(input("Please enter number of the automobile to be updated >> "))
automobile = automobiles.getAutomobile(index)
make = input("Please enter Make (enter 0 to skip) >> ")
model = input("Please enter Model (enter 0 to skip) >> ")
color = input("Please enter Color (enter 0 to skip) >> ")
year = int(input("Please enter Year (enter 0 to skip) >> "))
mileage = int(input("Please enter Mileage (enter -1 to skip) >> "))
if make!='0':
automobile.setMake(make)
print("Automobile make is updated")
if model!='0':
automobile.setModel(model)
print("Automobile model is updated")
if color!='0':
automobile.setColor(color)
print("Automobile color is updated")
if year!=0:
automobile.setYear(year)
print("Automobile year is updated")
if mileage!=-1:
automobile.setMileage(mileage)
print("Automobile mileage is updated")
# create automobile dealership object
automobiles = Automobiledealership()
choice = -1
# start loop
while choice!=0:
print()
print("1. Add sample automobiles to dealership")
print("2. Display automobiles in the dealership")
print("3. Add automobile to dealership")
print("4. Remove automobile from dealership")
print("5. Update automobile at dealership")
print("6. Export automobile Inventory")
print("0. Exit program")
choice = int(input("Your choice >> "))
print()
if choice==1:
addSampleAutomobiles(automobiles)
elif choice==2:
automobiles.printAutomobileList()
elif choice==3:
addAutomobile(automobiles)
elif choice == 4:
removeAutomobile(automobiles)
elif choice == 5:
updateAutomobile(automobiles)
elif choice == 6:
f = open('AutomobileList.txt', 'w')
f.write(str(automobilelist))
f.close()
您可以尝试在 class 中创建一个 getter 函数。
def getAutoMobileList(self):
return self.__automobilelist
你得到这个错误是因为 automobilelist 确实没有在 Automobiledealership class.[=19 的范围之外定义=]
如果您想从 class 中获取字段，您应该调用 <InstanceName>。<FieldName>，在你的情况下是 automobiles.__automobilelist.
但在你的情况下它仍然不起作用。当您在 __automobilelist 前加上双下划线时，您将其定义为 Automobiledealership class 的私有成员，因此您还应该为 automobilelist 创建一个 getter 函数（就像你对 getAutomobile 做的那样）
一个简单的 getter 函数，您可以在 class:
中使用
def getAutoMobileList(self):
return self.__automobilelist
然后调用automobiles.getAutoMobileList().
另一种解决方法：
你叫的是str(automobilelist)，上面说的应该是str(automobiles.getAutoMobileList())，又可以翻译成automobiles.__str__()。这意味着您可以定义一个 __str__ 函数来代替上面提到的 getter 函数。
因此，对于换行符分隔值，您可以定义：
def __str__(self):
return '\n'.join(str(i) for i in self.__automobilelist)
然后直接调用 str(automobiles).
如果用户 select 选择了该选项，我的部分任务是导出为文本。除了那一部分，我似乎什么都对。谁能建议我哪里出错了？我是否需要在代码中的其他地方添加一些东西才能正常工作？当我 select 选项 6 时，我收到 automobilelist 未定义的错误。
class Automobile:
# constructor, it takes parameters make, model, year and mileage
def __init__(self,aMake,aModel,aColor,aYear,aMileage):
# assign passed values to instance variables
self.setMake(aMake) # string
self.setModel(aModel) # string
self.setColor(aColor) # string
self.setYear(aYear) # int
self.setMileage(aMileage) # int
# setter of make
# it takes 1 parameter make
# it doesn't returns anything
def setMake(self, aMake):
self.__make = aMake
# getter of make
# it doesn't take any parameters
# it returns make
def getMake(self):
return self.__make
# setter of model
# it takes 1 parameter model
# it doesn't returns anything
def setModel(self, aModel):
self.__model = aModel
# getter of model
# it doesn't take any parameters
# it returns model
def getModel(self):
return self.__model
# setter of color
# it takes 1 parameter color
# it doesn't returns anything
def setColor(self, aColor):
self.__color = aColor
return True
# getter of color
# it doesn't take any parameters
# it returns color
def getColor(self):
return self.__color
# setter of year
# it takes 1 parameter year
# it doesn't returns anything
def setYear(self, aYear):
self.__year = aYear
# getter of year
# it doesn't take any parameters
# it returns year
def getYear(self):
return self.__year
# setter of mileage
# it takes 1 parameter year
# it doesn't returns anything
def setMileage(self, aMileage):
self.__mileage = aMileage
# getter of mileage
# it doesn't take any parameters
# it returns mileage
def getMileage(self):
return self.__mileage
# string representation of the instance variables
# it doesn't take any parameters
# it returns string form of object
def __str__(self):
return "{}, {}, {}, {}, {}".format(self.getMake(),self.getModel(),self.getColor(),self.getYear(),self.getMileage())
class Automobiledealership:
# constructor
# it initializes the empty automobile list
def __init__(self):
self.__automobilelist = []
# adds automobile to dealership
# it takes automobile class object as parameter
# it doesn't returns anything
def addAutomobile(self, automobile):
self.__automobilelist.append(automobile)
# removes automobile from dealership
# it takes index of automobile in the list as parameter
# it doesn't returns anything
def removeAutomobile(self, index):
del self.__automobilelist[index-1]
# returns automobile from dealership
# it takes index of automobile in the list as parameter
# it returns automobile object located at that index
def getAutomobile(self, index):
return self.__automobilelist[index-1]
# prints the list of automobiles
# it doesn't take any parameters
# it doesn't returns anything
def printAutomobileList(self):
if len(self.__automobilelist)==0:
print("No automobiles in dealership")
else:
for i in range(len(self.__automobilelist)):
print("{}. {}".format(i+1,self.__automobilelist[i]))
# add some automobiles to the dealership for Sample Inventory
def addSampleAutomobiles(automobiles):
automobiles.addAutomobile(Automobile("Ford", "Focus", "Red", 2019, 8000))
automobiles.addAutomobile(Automobile("Toyota","Corolla","White",2007,65000))
automobiles.addAutomobile(Automobile("Ford","Endura","Black",2019,5000))
automobiles.addAutomobile(Automobile("Audio","A1","White",2016,23000))
automobiles.addAutomobile(Automobile("Toyota", "Camry", "Red", 2000, 25000))
automobiles.addAutomobile(Automobile("Ford","Everest","Black",2017,16000))
automobiles.addAutomobile(Automobile("Mazda","MX5","Red",2015,33000))
automobiles.addAutomobile(Automobile("Ford","Escape","Grey",2018,15000))
automobiles.addAutomobile(Automobile("Toyota", "Prius", "Red", 2010, 35000))
def addAutomobile(automobiles):
make = input("Please enter Make >> ")
model = input("Please enter Model >> ")
color = input("Please enter Color >> ")
year = int(input("Please enter Year >> "))
mileage = int(input("Please enter Mileage >> "))
automobiles.addAutomobile(Automobile(make,model,color,year,mileage))
def removeAutomobile(automobiles):
index = int(input("Please enter number of the automobile to be removed >> "))
automobiles.removeAutomobile(index)
def updateAutomobile(automobiles):
index = int(input("Please enter number of the automobile to be updated >> "))
automobile = automobiles.getAutomobile(index)
make = input("Please enter Make (enter 0 to skip) >> ")
model = input("Please enter Model (enter 0 to skip) >> ")
color = input("Please enter Color (enter 0 to skip) >> ")
year = int(input("Please enter Year (enter 0 to skip) >> "))
mileage = int(input("Please enter Mileage (enter -1 to skip) >> "))
if make!='0':
automobile.setMake(make)
print("Automobile make is updated")
if model!='0':
automobile.setModel(model)
print("Automobile model is updated")
if color!='0':
automobile.setColor(color)
print("Automobile color is updated")
if year!=0:
automobile.setYear(year)
print("Automobile year is updated")
if mileage!=-1:
automobile.setMileage(mileage)
print("Automobile mileage is updated")
# create automobile dealership object
automobiles = Automobiledealership()
choice = -1
# start loop
while choice!=0:
print()
print("1. Add sample automobiles to dealership")
print("2. Display automobiles in the dealership")
print("3. Add automobile to dealership")
print("4. Remove automobile from dealership")
print("5. Update automobile at dealership")
print("6. Export automobile Inventory")
print("0. Exit program")
choice = int(input("Your choice >> "))
print()
if choice==1:
addSampleAutomobiles(automobiles)
elif choice==2:
automobiles.printAutomobileList()
elif choice==3:
addAutomobile(automobiles)
elif choice == 4:
removeAutomobile(automobiles)
elif choice == 5:
updateAutomobile(automobiles)
elif choice == 6:
f = open('AutomobileList.txt', 'w')
f.write(str(automobilelist))
f.close()
您可以尝试在 class 中创建一个 getter 函数。
def getAutoMobileList(self):
return self.__automobilelist
你得到这个错误是因为 automobilelist 确实没有在 Automobiledealership class.[=19 的范围之外定义=]
如果您想从 class 中获取字段，您应该调用 <InstanceName>。<FieldName>，在你的情况下是 automobiles.__automobilelist.
但在你的情况下它仍然不起作用。当您在 __automobilelist 前加上双下划线时，您将其定义为 Automobiledealership class 的私有成员，因此您还应该为 automobilelist 创建一个 getter 函数（就像你对 getAutomobile 做的那样）
一个简单的 getter 函数，您可以在 class:
中使用def getAutoMobileList(self):
return self.__automobilelist
然后调用automobiles.getAutoMobileList().
另一种解决方法：
你叫的是str(automobilelist)，上面说的应该是str(automobiles.getAutoMobileList())，又可以翻译成automobiles.__str__()。这意味着您可以定义一个 __str__ 函数来代替上面提到的 getter 函数。
因此，对于换行符分隔值，您可以定义：
def __str__(self):
return '\n'.join(str(i) for i in self.__automobilelist)
然后直接调用 str(automobiles).