Python3：如何使用While循环从列表中删除重复项

这是我目前的代码：

sandwich_orders = ['pbj ', 'pastrami ', 'ham ', 'blt ', 'pastrami ', 'knuckle ', 'pastrami ']
finished_sandwiches = []
print("Ordered sandwiches: " , sandwich_orders)

while sandwich_orders:
    complete_sandwiches = sandwich_orders.pop()
    print("Now making your  " + complete_sandwiches.title() + "sandwich")
    finished_sandwiches.append(complete_sandwiches.title())

for finished_sandwich in finished_sandwiches:
    print("Your " + finished_sandwich.title() + " sandwich is now ready.")

这是我运行程序时的当前程序输出：

    Ordered sandwiches:  ['pbj ', 'pastrami ', 'ham ', 'blt ', 'pastrami ', 'knuckle ', 'pastrami ']
Now making your  Pastrami sandwich
Now making your  Knuckle sandwich
Now making your  Pastrami sandwich
Now making your  Blt sandwich
Now making your  Ham sandwich
Now making your  Pastrami sandwich
Now making your  Pbj sandwich
Your Pastrami  sandwich is now ready.
Your Knuckle  sandwich is now ready.
Your Pastrami  sandwich is now ready.
Your Blt  sandwich is now ready.
Your Ham  sandwich is now ready.
Your Pastrami  sandwich is now ready.
Your Pbj  sandwich is now ready.

我正在尝试使用While循环从列表中删除“Pastrami”的所有实例，但我不太确定如何格式化它。我试着把这个代码放到上面的while循环中

sandwiches = [sandwich_orders , finished_sandwiches , complete_sandwiches]
    if 'pastrami' in sandwiches:
        sandwiches.remove('pastrami')

虽然代码运行时没有任何错误，但什么也没有发生。我真的希望输出结果如下：

---

您可以使用

set

数据类型，而不是使用while循环：

通过将列表转换为

set

数据类型，您可以确保集合中不会保留重复项，因为集合中不能有重复项，最后您可以将其转换回列表

---

您可以使用

set

数据类型，而不是使用while循环：

通过将列表转换为

set

数据类型，您可以确保集合中不会保留重复项，因为集合中不能有重复项，最后您可以将其转换回列表

使用熊猫可以：

sandwich_orders = ['pbj ', 'pastrami ', 'ham ', 'blt ', 'pastrami ', 'knuckle ', 'pastrami ']

# Create a pandas Series from the original list
sandwich_series =  pd.Series(sandwich_orders)

# Create a boolean series of items that were not duplicated
unique_bool = ~sandwich_series.duplicated(keep = False)
# 0    False
# 1     True
# 2    False
# 3    False
# 4     True
# 5    False
# 6     True
# dtype: bool

# Select the unique items from the series
sandwich_series[unique_bool].tolist()
# ['pbj ', 'ham ', 'blt ', 'knuckle ']

使用熊猫可以：

sandwich_orders = ['pbj ', 'pastrami ', 'ham ', 'blt ', 'pastrami ', 'knuckle ', 'pastrami ']

# Create a pandas Series from the original list
sandwich_series =  pd.Series(sandwich_orders)

# Create a boolean series of items that were not duplicated
unique_bool = ~sandwich_series.duplicated(keep = False)
# 0    False
# 1     True
# 2    False
# 3    False
# 4     True
# 5    False
# 6     True
# dtype: bool

# Select the unique items from the series
sandwich_series[unique_bool].tolist()
# ['pbj ', 'ham ', 'blt ', 'knuckle ']

---

您可以使用一个名为

new_sandwich_orders

的新列表，并存储

sandwich_orders

中具有一种外观的项目：

sandwich_orders = ['pbj ', 'pastrami ', 'ham ', 'blt ', 'pastrami ', 'knuckle ', 'pastrami ']
    finished_sandwiches = []
    new_sandwich_orders = []
    for s in sandwich_orders:
        if sandwich_orders.count(s) == 1:
            new_sandwich_orders.append(s)
print("Ordered sandwiches: " , new_sandwich_orders)

while new_sandwich_orders:
    complete_sandwiches = new_sandwich_orders.pop()
    print("Now making your  " + complete_sandwiches.title() + "sandwich")
    finished_sandwiches.append(complete_sandwiches.title())

for finished_sandwich in finished_sandwiches:
    print("Your " + finished_sandwich.title() + " sandwich is now ready.")

结果将是：

Ordered sandwiches:  ['pbj ', 'ham ', 'blt ', 'knuckle ']
Now making your  Knuckle sandwich
Now making your  Blt sandwich
Now making your  Ham sandwich
Now making your  Pbj sandwich
Your Knuckle  sandwich is now ready.
Your Blt  sandwich is now ready.
Your Ham  sandwich is now ready.
Your Pbj  sandwich is now ready.

---

您可以使用一个名为

new_sandwich_orders

的新列表，并存储

sandwich_orders

中具有一种外观的项目：

sandwich_orders = ['pbj ', 'pastrami ', 'ham ', 'blt ', 'pastrami ', 'knuckle ', 'pastrami ']
    finished_sandwiches = []
    new_sandwich_orders = []
    for s in sandwich_orders:
        if sandwich_orders.count(s) == 1:
            new_sandwich_orders.append(s)
print("Ordered sandwiches: " , new_sandwich_orders)

while new_sandwich_orders:
    complete_sandwiches = new_sandwich_orders.pop()
    print("Now making your  " + complete_sandwiches.title() + "sandwich")
    finished_sandwiches.append(complete_sandwiches.title())

for finished_sandwich in finished_sandwiches:
    print("Your " + finished_sandwich.title() + " sandwich is now ready.")

结果将是：

Ordered sandwiches:  ['pbj ', 'ham ', 'blt ', 'knuckle ']
Now making your  Knuckle sandwich
Now making your  Blt sandwich
Now making your  Ham sandwich
Now making your  Pbj sandwich
Your Knuckle  sandwich is now ready.
Your Blt  sandwich is now ready.
Your Ham  sandwich is now ready.
Your Pbj  sandwich is now ready.

---

三明治订单中的“熏牛肉”后面有空格

sandwich_orders = ['pbj ', 'pastrami ', 'ham ', 'blt ', 'pastrami ', 'knuckle ', 'pastrami ']

---

三明治订单中的“熏牛肉”后面有空格

sandwich_orders = ['pbj ', 'pastrami ', 'ham ', 'blt ', 'pastrami ', 'knuckle ', 'pastrami ']

---

如果您想维持秩序，您可以尝试：

sandwiches = [sandwich_orders, finished_sandwiches, complete_sandwiches]
sandwiches_new = [[i for i in x if i!='pastrami'] for x in sandwiches]

---

集合本质上是无序的。

如果您想保持顺序，可以尝试：

sandwiches = [sandwich_orders, finished_sandwiches, complete_sandwiches]
sandwiches_new = [[i for i in x if i!='pastrami'] for x in sandwiches]

---

套装本质上是无序的。

你已经从

三明治中移除了
熏牛肉
，但是你在
三明治订单
上循环运行，其中仍然包含
熏牛肉
，我不明白。看到我发布的答案，你首先需要从
三明治订单
中移除
熏牛肉
，然后在它上面循环你已经从
三明治中移除了
pastrami
，但是你正在运行
sandwich\u orders
，其中仍然包含
pastrami
，我不明白？看到我发布的答案，你首先需要从
sandwich\u orders中移除
pastrami
，然后在itBTW上循环，pop（）从最后一个位置弹出元素，if语句从第一个元素中删除，根据列表的顺序，最后一个“pastrami”在被删除之前被追加到“finished_sandwiches”中。我在第一个循环上方创建了另一个“while”循环，以引用“三明治订单”列表中的“pastrami”，并将“.remove（）”应用于该列表。由于缺少空格，整个时间都在浪费。顺便说一句，pop（）会从最后一个位置弹出元素，而if语句会从第一个元素中删除，根据列表的顺序，最后一个“pastrami”会在被删除之前附加到“finished_sandwiches”中。我在第一个循环上方创建了另一个“while”循环，以引用“三明治订单”列表中的“pastrami”，并将“.remove（）”应用于该列表。因为没有空间，整个时间都在浪费空间。