如何从对象创建列表

Question

我有一个清单程序，它从 excel 文件中读取列表，然后创建一个类。我想覆盖列表中对象的新值，然后将列表导出到 excel。在这里，我从 excel 文件中导入列表import pandas as pddf = pd.read_excel('stock.xlsx')inventory_code = df['code'].tolist()inventory_name= df['name'].tolist()inventory_amount = df['amount'].tolist()inventory_unit = df["birim"].tolist()inventory_location=df["location"].tolist()然后我创建类class Inventory:    def __init__(self,i_code,i_amount,i_unit,i_location):        self.i_code=i_code        self.i_amount=i_amount        self.i_unit=i_unit        self.i_location=i_location    def info(self):        print("Product code:", self.i_code, "Amount:", self.i_amount, "Unit:", self.i_unit, "Place:", self.i_location)    def add(self, add_amount):        self.i_amount += add_amount    def update(self):        mylist2.append(self.i_amount)        for i in range(0,len(inventory_name)):    globals()[inventory_name[i]]=Inventory(inventory_code[i],inventory_amount[i],inventory_unit[i],inventory_location[i])现在，我想创建一个新列表 mylist2，其中包含以前的库存量和 folyo 的新值。mylist2=[]folyo.info()folyo.add(999999)folyo.update()folyo.info()print(mylist2)在此代码中，输出如下：Product code: 0 Amount: 500 Unit: m2 Place: storage_1Product code: 0 Amount: 1000499 Unit: m2 Place: storage_1[1000499]但是，我的更新命令仅保存提到的内容，在本例中为 amount folyo。我想保存所有对象。我该如何解决这个问题？我认为只更新相关的东西可以是一个解决方案。但是，我的解决方案只给出了一个空列表。    def update(self):        for i in range(0, len(mylist2)):            if inventory_code[i] == self.i_code:                mylist2[i]= self.i_amount            else:                pass

Answer 1

解决方法如下：

import pandas as pd

df = pd.read_excel('stock.xlsx')

inventory_code = df['code'].tolist()

inventory_name= df['name'].tolist()

inventory_amount = df['amount'].tolist()

inventory_unit = df["birim"].tolist()

inventory_location=df["location"].tolist()

class Inventory:

    def __init__(self,i_code,i_amount,i_unit,i_location):

        self.i_code=i_code

        self.i_amount=i_amount

        self.i_unit=i_unit

        self.i_location=i_location

    def info(self):

        print("Product code:", self.i_code, "Amount:", self.i_amount, "Unit:", self.i_unit, "Place:", self.i_location)

    def add(self, add_amount):

        self.i_amount += add_amount

    def update(self):

        for i in range(0, len(inventory_name)):

            if inventory_code[i] == self.i_code:

                mylist2.append(self.i_amount)

            else:

                mylist2.append(inventory_amount[i])

for i in range(0,len(inventory_name)):

    globals()[inventory_name[i]]=Inventory(inventory_code[i],inventory_amount[i],inventory_unit[i],inventory_location[i])

mylist2=[]

folyo.info()

folyo.add(4000)

folyo.update()

folyo.info()

print(mylist2)

print(len(inventory_amount))

print(len(mylist2))

Answer 2

解决方法如下：

import pandas as pd

df = pd.read_excel('stock.xlsx')

inventory_code = df['code'].tolist()

inventory_name= df['name'].tolist()

inventory_amount = df['amount'].tolist()

inventory_unit = df["birim"].tolist()

inventory_location=df["location"].tolist()

class Inventory:

    def __init__(self,i_code,i_amount,i_unit,i_location):

        self.i_code=i_code

        self.i_amount=i_amount

        self.i_unit=i_unit

        self.i_location=i_location

    def info(self):

        print("Product code:", self.i_code, "Amount:", self.i_amount, "Unit:", self.i_unit, "Place:", self.i_location)

    def add(self, add_amount):

        self.i_amount += add_amount

    def update(self):

        for i in range(0, len(inventory_name)):

            if inventory_code[i] == self.i_code:

                mylist2.append(self.i_amount)

            else:

                mylist2.append(inventory_amount[i])

for i in range(0,len(inventory_name)):

    globals()[inventory_name[i]]=Inventory(inventory_code[i],inventory_amount[i],inventory_unit[i],inventory_location[i])

mylist2=[]

folyo.info()

folyo.add(4000)

folyo.update()

folyo.info()

print(mylist2)

print(len(inventory_amount))

print(len(mylist2))