删除特定值的所有实例

Question

我正在尝试从列表中删除特定值的所有实例，然后将剩余的列表项向下移动。该代码在某些情况下有效，但在其他情况下无效。例如：

print(myremove([7, 'B', 1, 8, 3, 'B'], 6, 'B')) # Gets what I want 
print(myremove(['C', 'C', 7, 'C', 4, 'C'], 6, 'C')) # Does not

我想做的一件事是删除该项目的所有实例，然后将所有剩余元素向下移动。

   def myremove(mylist, elements, item):
        for i in range(elements):
            if mylist[i] == item:
                 mylist[i] = None
                 elements-= 1

        for i in range(elements):
            if mylist[i] is None:
                for j in range(i, elements):
                    mylist[j] = mylist[j + 1]
                    mylist[elements] = None

        return mylist

Answer 1

解决方案

您可以使用简单的 Pythonic 列表推导：

vals = ['C', 'C', 7, 'C', 4, 'C']
droplist = [6, 'C']
[x for x in vals if (x not in droplist)]

修改myremove()函数

def myremove(vals, droplist = None):
    if droplist is None:
        droplist = [None, ]
    return [x for x in vals if (x not in droplist)]

print(myremove([7, 'B', 1, 8, 3, 'B'], droplist=[8, 'B']))
print(myremove(['C', 'C', 7, 'C', 4, 'C'], droplist=[6, 'C']))

输出：

[7, 1, 3]
[7, 4]