我有一个字典restaurants
,并且想根据用户输入的日期来更改opening hours
中嵌套列表中closing hours
和restaurants
的值。
opening_time=0
closing_time=0
##snippet of the dictionary
restaurants={"Macdonald's":\
\
[{"Monday":[700,2400],\
"Tuesday":[700,2400],\
"Wednesday":[700,2400],\
"Thursday":[700,2400],\
"Friday":[700,2400],\
"Saturday":[700,2400],\
"Sunday":[1000,2200]},\
\
"Block XXX, #01-XX",\
"Fast food restaurant known for its all round excellent menu.",\
\
["Breakfast",[opening_time,1100],\
{"Egg McMuffin":"$1",\
"Hotcakes":"$1",\
"Big Breakfast":"$1"}],\
["Lunch/Dinner",[1100,closing_time],\
{"Double Cheeseburger":"$3.20",\
"McChicken":"$3.95",\
"Big Mac":"$4.70",\
"Chicken McNuggets (6pcs)":"$4.95",\
"McWings":"$4.95"}],\
["All Day",[opening_time,closing_time],\
{"Fillet-O-Fish":"$4.60",\
"Corn Cup":"$1.95"}]]}
我希望代码循环遍历并打印所有餐厅和菜单,同时指示在用户输入的时间是否可以使用这些餐厅和菜单。
for key in restaurants: #key refers to restaurant name
print("","",sep='\n')
if day_now in restaurants.get(key)[0].keys(): #check if restaurant is open on that day
opening_time=restaurants.get(key)[0][day_now][0] #set opening and closing hours to those on that day
closing_time=restaurants.get(key)[0][day_now][1]
if time_now>=opening_time and time_now<closing_time: #check if restaurant is open within that time period
status="Open"
open_restaurants.update(restaurants)
print(key,"Status: "+status,"Opening Hours Today:"+str(opening_time)+" to "+str(closing_time),\
"Location: "+restaurants.get(key)[1],"Description: "+restaurants.get(key)[2],sep='\n')
for i in range(3, len(restaurants.get(key))): #goes through the menus the restaurant has
print(restaurants.get(key)[i][1][0]) #prints 0
print(restaurants.get(key)[i][1][1]) #prints 0
if time_now>=restaurants.get(key)[i][1][0] and time_now<restaurants.get(key)[i][1][1]: #check if menu have
print("")
print(restaurants.get(key)[i][0]+" Menu: Available","Item: Cost:",sep='\n')
for item in restaurants.get(key)[i][2].keys():
print(item, restaurants.get(key)[i][2][item],sep=' ')
else:
print("")
print(restaurants.get(key)[i][0]+" Menu: Unavailable","Item: Cost:", sep='\n')
for item in restaurants.get(key)[i][2].keys():
print(item, restaurants.get(key)[i][2][item],sep=' ')
else:
closed_restaurants.update(restaurants)
status="Closed"
print(key,"Status: "+status,"Opening Hours Today:"+str(opening_time)+" to "+str(closing_time),\
"Location: "+restaurants.get(key)[1],"Description: "+restaurants.get(key)[2], sep='\n')
else:
closed_restaurants.update(restaurants)
status="Closed"
print(key,"Status: "+status,"Opening Hours Today:"+str(opening_time)+" to "+str(closing_time),\
"Location: "+restaurants.get(key)[1],"Description: "+restaurants.get(key)[2], sep='\n')
print(opening_time) #prints the correct opening and closing hours
print(closing_time)
但是,字典中的opening hours
和closing hours
变量无法在循环中分配给所需的值,并保持不变,因为它们是第一次在循环外部分配的。
直接打印变量名表明新值已成功分配。
有人可以在这里帮助我解决这个问题吗?谢谢。
答案 0 :(得分:0)
让我们使用这个简单的例子来弄清楚您的假设在哪里错误:
var = 1
lst = [var]
var = 2
print(lst)
[1]
或[2]
应该打印什么?它将打印[1]
。您这里没有的不是变量引用列表,而是整数列表。您采用了var
的值,并将其放入列表中。副本,如果需要的话。
那呢?
a = 1
b = a
a = 2
同样,此后b
仍然是1
。您将写入的内容存储在a
的位置,并将其放置在存储b
的位置。
您实际上需要更新字典中的值,而仅更新opening_hours
是不够的。