全部是Python的数据结构和算法的新手。我在广告资源计划中实现了插入和气泡排序。在对当前词典进行排序时，插入和冒泡排序都可以使用。但是，在添加新项目或从字典中删除项目之后，我的插入和冒泡排序获得了关键错误。我曾尝试将字典更改为[{description ..}]，并且之前也将market [len（market）+ 1]更改为market [len（market）]。这些都不起作用。如果有人帮助我编辑代码或向我解释发生了什么，我将非常感谢。预先谢谢您：“）
market = {0: {'Description': 'Chocolate', 'Stock': 65, 'Price': 3.2, 'Expiry': '27 Dec', 'Discount': 'eligible'},
1: {'Description': 'Bread', 'Stock': 20, 'Price': 2.7, 'Expiry': '15 June', 'Discount': 'eligible'},
2: {'Description': 'Apples', 'Stock': 97, 'Price': 10.6, 'Expiry': '12 July', 'Discount': 'not eligible'},
3: {'Description': 'Potato', 'Stock': 81, 'Price': 20.8, 'Expiry': '13 April', 'Discount': 'not eligible'},
4: {'Description': 'Ice', 'Stock': 91, 'Price': 9.8, 'Expiry': '16 April', 'Discount': 'not eligible'}
}
def menu():
print('Press 1: To Add items. ')
print('Press 2: To View items. ')
print('Press 3: To Remove items. ')
print('Press 4: Use Insertion Sort. ')
print('Press 5: Use Bubble Sort. ')
print('Press 6: Use Binary Search. ')
print('Press 7: View Total and Average stock level. ')
print('Press q: To Quit program. ')
return input('What would you like to do? ')
# print(len(market) + 1) # check counter
# Insertion Sort
def insertionSort(theSeq, key):
for i in range(1, len(theSeq)):
temp = theSeq[i][key]
j = i
while j > 0 and temp < theSeq[j - 1][key]:
theSeq[j][key] = theSeq[j - 1][key]
j = j - 1
theSeq[j][key] = temp
return theSeq
# Sorting Menu
def sort_menu(second_list, sort_type):
print('1. Sort by Description')
print('2. Sort by Price')
# Get user input
user_input = input('Please enter choice: ')
if user_input == '1':
second_list = sort_type(second_list, 'Description')
print('Success! Inventory list is sorted by Description!')
elif user_input == '2':
second_list = sort_type(second_list, 'Price')
print('Success! Inventory list is sorted by Price!')
else:
print('You have entered an invalid option!')
# Return updated list
return second_list
# Bubble Sort
def bubble_sort(second_list, key):
# Create temp copy of list
temp = second_list.copy()
# Obtain length of list
y = len(temp)
for i in range(y - 1, 0, -1):
for j in range(i):
if temp[j][key] > temp[j + 1][key]:
temp[j], temp[j + 1] = temp[j + 1], temp[j]
# Return updated list
return temp
# Binary Search
def binarysearch(dictionary,item):
global founditem
itemlist = []
for item2 in dictionary:
itemlist.append(item2)
first = 0
last = len(itemlist) - 1
found = False
while first <= last and not found:
midpoint = (first + last)//2
if itemlist[midpoint] == item:
# print(midpoint) test print out
founditem = dictionary.get(midpoint)
found = True
else:
if item < itemlist[midpoint]:
last = midpoint-1
else:
first = midpoint+1
return founditem
# Print total and average stock level
def average(market):
n = len(market)
total = 0
for i in range(0,n):
total += market[i]["Stock"]
average = total/n
return average
def total(market):
n = len(market)
total = 0
for i in range(0,n):
total += market[i]["Stock"]
return total
while True:
run = menu()
if run == '1':
# market[len(market) + 1] = {}
# addMarket = input('Item to be added to Market? ')
# market[len(market) + 1]['Description'] = addMarket
name = input('Item to be added to Market? ')
price = float(input('Price of food?'))
amount = int(input('Qty of food to be added to stock? '))
expiry = input('Enter expiry date: ')
discount = input('Enter eligibility of discount: ')
market[len(market) + 1] = {'Description': name, 'Stock': amount, 'Price': price, 'Expiry': expiry,
'Discount': discount}
elif run == '2':
for i in market:
item = market[i]
print("Item No - %d Description - %s Stock - %d Price - %.2f Expiry - %s Discount - %s" % (
i, item['Description'], item['Stock'], item['Price'], item['Expiry'], item['Discount']))
elif run == '3':
remove = int(input('Key in item number to remove: '))
del market[remove]
elif run == '4':
market = sort_menu(market, insertionSort)
elif run == '5':
market = sort_menu(market, bubble_sort)
#
elif run == '6':
key = int(input('Enter key you want to search: '))
print(binarysearch(market, key))
elif run == '7':
print('')
print('Total stock level is',total(market), 'and Average stock level is', average(market))
print('')
else:
quit = str()
while quit.upper() != "Q":
quit = input("Enter Q or q to return to Main Menu. ")
if quit.upper() == "Q":
print('Thank you for using MamaStore!')
menu()
插入代码的问题是，您通过跳过每次插入一个索引来插入新元素。最初市场的大小为5，所以当您插入新元素时，该元素应位于索引5（起始索引为0），但market [len（market）+1]则插入索引6。因此，当您在排序中运行顺序循环时因为您没有5作为密钥，所以会引发密钥错误。类似地，在删除任何项目时，在删除过程中，序列中断会导致键错误，就像在插入情况下一样。您可能应该考虑在字典的键（在您的情况下是那些项ID）上运行循环。希望对您有所帮助！
您正在混合使用键和索引的概念。当您添加项目时，您给它指定密钥len（market）+ 1，即5 +1。因此，密钥“ 5”未使用，您将获得包含密钥1，2，3，4，6的字典
下一次，当您开始排序时，尝试将这些键用作索引。您要遍历连续范围的整数（y-1，0，-1），因此key ='5'上的键错误。您应该遍历键。要获取字典的索引，请使用例如
for i, d in enumerate(market):...
删除项目时也会发生相同的问题。密钥被删除，留下带有例如密钥的字典：0、1、2、4。您现在在key ='3'
上遇到密钥错误希望这会提供足够的线索来纠正您的脚本。