构建一个简单的待办事项列表应用程序以自学课程。几乎所有东西都可以工作（到目前为止，您可以添加项目，查看列表和删除项目）。但是，我似乎无法弄清楚如何实现更改项功能。本来应该更改已经创建的项目的名称，但是我正在处理的代码没有做到这一点。
# counters for telling if a slot is empty or not
a = 0
b = 0
c = 0
d = 0
e = 0
# overarching class for entire program
# outlines how a list item is structured
class Item():
def __init__(self, thingToDo, dueDate, priority):
self.thingToDo = thingToDo
self.dueDate = dueDate
self.priority = priority
def thingChange(self):
thingChange = input("What would you like to change it to? ")
self.thingToDo = thingChange
def whatToChange():
global whatToChange
whatToChange = input("What in the item would you like to change (1. thing, 2. due date, 3. priority)?")
if "1" in whatToChange:
itemChange = input("What would you like to change it to? ")
item1.thingToDo = itemChange
printCurrentList()
# takes inputs to add an instance of to do item
def getItem():
global thing
thing = input("What do you want to do?")
global time
time = input("When do you need to do it by?")
global importance
importance = input("Priority (rate out of 5): ")
# each of these takes the inputs from getItem(), and puts them into the slots
def runItem1():
getItem()
global item1
item1 = Item(thing, time, importance)
print("1. You need to " + item1.thingToDo + " by " + item1.dueDate + ", and the priority is " + item1.priority + "/5.")
global a
a = a + 1
def runItem2():
getItem()
global item2
item2 = Item(thing, time, importance)
print("2. You need to " + item2.thingToDo + " by " + item2.dueDate + ", and the priority is " + item2.priority + "/5.")
global b
b = b + 1
def runItem3():
getItem()
global item3
item3 = Item(thing, time, importance)
print("3. You need to " + item1.thingToDo + " by " + item1.dueDate + ", and the priority is " + item1.priority + "/5.")
global c
c = c + 1
def runItem4():
getItem()
global item4
item4 = Item(thing, time, importance)
print("4. You need to " + item4.thingToDo + " by " + item4.dueDate + ", and the priority is " + item4.priority + "/5.")
global d
d = d + 1
def runItem5():
getItem()
global item5
item5 = Item(thing, time, importance)
print("5. You need to " + item5.thingToDo + " by " + item5.dueDate + ", and the priority is " + item5.priority + "/5.")
global e
e = e + 1
# pretty self explanatory, prints out the current slots in a list-type format
def printCurrentList():
if a > 0:
print("1. You need to " + item1.thingToDo + " by " + item1.dueDate + ", and the priority is " + item1.priority + "/5.")
else: print("Slot 1 is empty.")
if b > 0:
print("2. You need to " + item2.thingToDo + " by " + item2.dueDate + ", and the priority is " + item2.priority + "/5.")
else:
print("Slot 2 is empty.")
if c > 0:
print("3. You need to " + item1.thingToDo + " by " + item1.dueDate + ", and the priority is " + item1.priority + "/5.")
else:
print("Slot 3 is empty.")
if d > 0:
print("4. You need to " + item4.thingToDo + " by " + item4.dueDate + ", and the priority is " + item4.priority + "/5.")
else:
print("Slot 4 is empty.")
if e > 0:
print("5. You need to " + item5.thingToDo + " by " + item5.dueDate + ", and the priority is " + item5.priority + "/5.")
else:
print("Slot 5 is empty.")
# adds an item to the list, but first, checks to see if list slots are already used -- uses a,b,c,d,e
def add():
printCurrentList()
if a > 0 and b > 0 and c > 0 and d > 0 and e > 0:
print("You need to empty a slot before you add another item.")
whichToRemove = input("Which slot would you like to remove?")
if input == "1":
print("What would you like to add in its place?")
runItem1()
else:
slot = input("Which slot would you like to use?: ")
if slot == "1":
runItem1()
elif slot == "2":
runItem2()
elif slot == "3":
runItem3()
elif slot == "4":
runItem4()
elif slot == "5":
runItem5()
else:
print("Error. Please try again.")
add()
# main loop of the program
def main():
prompt = input("What do you want to do (add, remove, change, or view)?: ")
if prompt == "add":
add()
elif prompt == "remove":
printCurrentList()
whichToRemove = input("Which one would you like to remove?: ")
if whichToRemove == "1":
print("Item 1, " + item1.thingToDo + ", has been removed.")
global a
a = 0
elif whichToRemove == "2":
print("Item 2, " + item2.thingToDo + ", has been removed.")
global b
b = 0
elif whichToRemove == "3":
print("Item 3, " + item3.thingToDo + ", has been removed.")
global c
c = 0
elif whichToRemove == "4":
print("Item 4, " + item4.thingToDo + ", has been removed.")
global d
d = 0
elif whichToRemove == "5":
print("Item 5, " + item5.thingToDo + ", has been removed.")
global e
e = 0
printCurrentList()
elif prompt == "view":
print("Here is your current list: ")
printCurrentList()
elif prompt == "change":
whichToChange = input("Which one would you like to change?: ")
if "1" in whichToChange:
oldItem = item1.thingToDo
whatToChange()
thingChange()
print("Item 1, " + oldItem + ", has been changed to " + item1.thingToDo)
elif "2" in whichToChange:
print("Item 2, " + item2.thingToDo + ", has been changed to _____________.")
elif "3" in whichToChange:
print("Item 3, " + item3.thingToDo + ", has been changed to _____________.")
elif "4" in whichToChange:
print("Item 4, " + item4.thingToDo + ", has been changed to _____________.")
elif "5" in whichToChange:
print("Item 5, " + item5.thingToDo + ", has been changed to _____________.")
printCurrentList()
main()
main()
有没有办法使它工作？
答案 0 :(得分：0)
似乎您正在将过程方法与面向对象的方法混合在一起。 面向对象设计的原则之一是确定功能所属的位置...哪些功能属于哪个类。 一旦我自己解决了这个问题，从对过程的思考就转向对对象的思考对我来说变得容易得多。
我建议创建一个列表[]或一个字典{}来存储您的物品。
然后可以通过
处理当前列表item_list = []
# ... create items and add to item_list using item_list.append(item)
for item in item_list:
print(item)
或
item_dictionary = {}
# create items and add to item_dictionary using item_dictionary[some_key] = item
for key in item_dictionary:
item = item_dictionary[key]
然后添加项目类所需的任何功能，并使用方法在字典列表中添加/删除/编辑这些项目。
我也会按照评论员的建议放下全局变量。我在编写的python代码中根本不使用全局变量。