Question

我正在尝试创建清单清单字典。示例我将'fruits', 'vegetables', 'drinks'添加为字典的键，然后为每个键创建一个列表。创建完成后，我为每个列表添加两个项目(e.g. 'apple','manggo')，以便可以像这样将它们打印出来：

fruits is list
items in fruits are apple, manggo
veggies is list
items in veggies are cabbage, cucumber
drinks is list
items in drinks are iced tea, juice

但是我无法识别新创建列表的项目，我只能得到这个：

fruits is list
items in fruits are fruits

我的代码：

class Inventory:


    def __init__(self):

        self.dict_inv = dict()
        self.count_inv = int(input("Enter the number of inventories: "))


        for count in range(self.count_inv):

            self.name_inv = str(input("Enter Inventory #%d: " % (count+1)))
            self.dict_inv[self.name_inv] = count
            self.name_inv = list()

            sample_add = str(input("Add item here: "))
            self.name_inv.append(sample_add)

            sample_add2 = str(input("Add another item here: "))
            self.name_inv.append(sample_add2)


        for keys in self.dict_inv.keys():
            if type([keys]) is list:
                print("%s is list" % keys)
                print("items in %s are %s" % (keys,str(keys)))


Inventory()

Answer 1

您应该测试您的实际列表，而不是从dict获得的keys（）-view列表：

class Inventory:


    def __init__(self):

        self.dict_inv = dict()
        self.count_inv = int(input("Enter the number of inventories: "))


        for count in range(self.count_inv):

            name_inv = str(input("Enter Inventory #%d: " % (count+1)))

            # simply add the list here 
            self.dict_inv[name_inv] = []

            sample_add = str(input("Add item here: "))
            # simply add empty list for that key directly, no need to store count here 
            self.dict_inv[name_inv].append(sample_add)

            sample_add2 = str(input("Add another item here: "))
            # simply append to the list here 
            self.dict_inv[name_inv].append(sample_add2)

        for key in self.dict_inv.keys():

            # dont create a list of one single key, use the dicts value instead
            if type(self.dict_inv[key]) is list:
                print("{} is list".format(key) )
                print("items in {} are {}".format(key, self.dict_inv[key]))


Inventory()

2,egg,1,2,tomato,3,4输入的输出：

egg is list
items in egg are ['1', '2']
tomato is list
items in tomato are ['3', '4']

使用以下命令更改输出：

print("items in {} are {}".format(key, ', '.join(self.dict_inv[key])))

更接近所需的输出：

egg is list
items in egg are 1, 2
tomato is list
items in tomato are 3, 4

HTH

Answer 2

在最后一行中，实际上是在同一处打印两次。首先，您要打印密钥，然后将其转换为字符串并打印。

将最后一行更改为以下内容：

C:\wamp64\bin\php\php5.6.38

这里for key in self.dict_inv.keys(): if type(self.dict_inv[key]) is list: print("%s is list" % key) print("items in %s are %s" % (key, *self.dict_inv[key])))正在访问列表，而前面的self.dict_inv[key]则将其暴露给列表中的每个项目，而不仅仅是列表本身！

旁注：我认为现在在python 3+中首选使用*而不是.format()，但这是重点。

Python 3：如何搜索根据用户输入创建的列表？

2 个答案: