在列表中，根据索引值执行任务？

Question

好的，所以我一直在尝试获取列表“bean”中的特定索引，以根据该索引的值执行任务。

下面是代码：

def dude():
    beans = ['639', '939']
    bun = 0
    heyo_beans = beans[bun]
    while bun in range(len(beans)):   
        while bun in range(len(beans)):
            try:
                b = heyo_beans.index('639')
            except ValueError:
                print("Do Nothing")
                break
            else:
                print("Do something with variable b")
                break
        bun = bun + 1
        print(bun)
    print(beans[1])
dude()

输出：

Do something with variable b
1
Do something with variable b
2
939

我应该得到：

Do something with variable b
1
Do Nothing
2
939

“Do Nothing”应该出现在第二次循环中，因为索引更改为索引 2，即 939。 最终输出939是为了验证bean索引1确实是939。 有什么想法吗？

另一个例子是：

list = ['111', '222', '333']
#goes through the list in a while loop, each time adding +1 index, for range in length
if list index = 111:
    "Perform task A"
elif list index = 222:
    "Perform task B"
elif list index = 333:
    "Perform task C"
else:
    "Do Nothing"
list index = index + 1

关于如何进行这项工作有什么建议吗？

这也不起作用：

def dude():
    list_to_beans = ['639', '939']
    bun = 0
    heyo_beans = list_to_beans[bun]
    while bun in range(len(list_to_beans)):   
        for bun in list_to_beans:
            if heyo_beans == '639':
                print("Do something")
            else:
                print("Do nothing")
        bun = bun + 1
    print(bun)

    
dude()

输出：

Do something
Do something

应该说：

Do something
Do nothing
2

Answer 1

答案：

def dude():
    list_to_beans = ['639', '939']
    bun = 0
    heyo_beans = list_to_beans[bun]
       
    for heyo_beans in list_to_beans:
        if heyo_beans == '639':
            print("Do something")
        else:
            print("Do nothing")
    bun = bun + 1
    print(bun)

    
dude()

输出：

Do something
Do Nothing
1

Answer 2

你让这种方式变得比需要的更加复杂。只需使用普通的 for 循环即可迭代列表的所有元素。您将索引与元素混淆了。

由于列表包含字符串，因此您必须与字符串进行比较，而不是与数字进行比较。

mylist = ['111', '222', '333']
for item in mylist:
    if item == '111':
        "Perform task A"
    elif item == '222':
        "Perform task B"
    elif item == '333':
        "Perform task C"
    else:
        "Do Nothing"