Python append（）似乎正在重写列表中的值

我保存了一个CSV文件，其中有三个商店（商店a、B和C）。有多行商品，行中的单元格中有值，指示商店是否销售该商品

我试图浏览每一行，我的目标是找到只有一家商店出售的商品（商店特有的商品）

如果有一个商店独有的项目，我想将该项目附加到列表中（我为每个商店都有一个）

我的问题是，当我打印带有我的条件的所有项目时，它会向我显示商店特有的所有项目，但是当我将它们附加到我的列表并打印我的列表时，只会显示最后一个项目（这就是我认为它被覆盖的原因）

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您正在导致问题的每个迭代中创建一个新列表

请尝试以下操作：

import csv
reader = csv.DictReader(open("storeLists.csv"))
storeAuniqueItems = []
storeBuniqueItems = []
storeCuniqueItems = []
for row in reader:
    STORES = [row]
    "COMPARING ALL THE SHOPS TO GATHER ALL THE UNIQUE ITEMS OF EACH SHOP AND SAVE THE INTO A LIST"

    if row["STORE A"] == "Y" and row["STORE B"] != "Y" and row["STORE C"] != "Y":
             storeAuniqueItems.append(row["NAME"])


    elif row["STORE A"] != "Y" and row["STORE B"] == "Y" and row["STORE C"] != "Y":
            storeBuniqueItems.append(row["NAME"])


    elif row["STORE A"] != "Y" and row["STORE B"] != "Y" and row["STORE C"] == "Y":
            storeCuniqueItems.append(row["NAME"])


    else:
            print("NaN")
print("STORE A:", storeAuniqueItems)
print("STORE B:", storeBuniqueItems)
print("STORE C:", storeCuniqueItems)

import csv
reader = csv.DictReader(open("storeLists.csv"))
storeAuniqueItems = []
storeBuniqueItems = []
storeCuniqueItems = []
for row in reader:
    STORES = [row]
    "COMPARING ALL THE SHOPS TO GATHER ALL THE UNIQUE ITEMS OF EACH SHOP AND SAVE THE INTO A LIST"

    if row["STORE A"] == "Y" and row["STORE B"] != "Y" and row["STORE C"] != "Y":
             storeAuniqueItems.append(row["NAME"])


    elif row["STORE A"] != "Y" and row["STORE B"] == "Y" and row["STORE C"] != "Y":
            storeBuniqueItems.append(row["NAME"])


    elif row["STORE A"] != "Y" and row["STORE B"] != "Y" and row["STORE C"] == "Y":
            storeCuniqueItems.append(row["NAME"])


    else:
            print("NaN")
print("STORE A:", storeAuniqueItems)
print("STORE B:", storeBuniqueItems)
print("STORE C:", storeCuniqueItems)