如何从列表中删除特定项目？

html5 • • 问答

我正在尝试从菜单上的给定选项中删除垃圾邮件，我的for循环不起作用。

menu = [
    ["egg", "bacon"],
    ["egg", "sausage", "bacon"],
    ["egg", "spam"],
    ["egg", "bacon", "spam"],
    ["egg", "bacon", "sausage", "spam"],
    ["spam", "bacon", "sausage", "spam"],
    ["spam", "sausage", "spam", "bacon", "spam", "tomato", 
    "spam"],
    ["spam", "egg", "spam", "spam", "bacon", "spam"],
]

for choice in menu:
    if "spam" in choice:
        remove("spam")
        print(choice)

回答

正如@h4z4 所述，remove未定义。尝试

for choice in menu:
    if "spam" in choice:
        choice.remove("spam")
        print(choice)

但是，remove仅删除第一次出现。要删除所有出现，请尝试：

for choice in menu:
    if "spam" in choice:
        choice = [item for item in choice if item != "spam"]
        print(choice)

回答

要从子列表中删除所有“垃圾邮件”，请使用列表理解：

menu = [
    ["egg", "bacon"],
    ["egg", "sausage", "bacon"],
    ["egg", "spam"],
    ["egg", "bacon", "spam"],
    ["egg", "bacon", "sausage", "spam"],
    ["spam", "bacon", "sausage", "spam"],
    ["spam", "sausage", "spam", "bacon", "spam", "tomato", "spam"],
    ["spam", "egg", "spam", "spam", "bacon", "spam"],
]

menu = [[val for val in subl if val != "spam"] for subl in menu]
print(menu)

印刷：

[['egg', 'bacon'], 
 ['egg', 'sausage', 'bacon'], 
 ['egg'], 
 ['egg', 'bacon'], 
 ['egg', 'bacon', 'sausage'], 
 ['bacon', 'sausage'], 
 ['sausage', 'bacon', 'tomato'], 
 ['egg', 'bacon']]

以上是如何从列表中删除特定项目？的全部内容。
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