从列表列表中删除所有匹配的值

Question

我有以下列表对象列表

myList = [[123,0.0,345,0.0,0.0,0.0],
 [45,0.0,0.0,0.0],
 [67,8,0.0,5,6,7,0.0]

我想从此列表中删除所有零。

我遵循了这个问题，并按如下所示进行编码。

myList = list(filter(lambda j:j!=0,myList[i]) for i in range(len(myList)))

但是我正在获取过滤器对象列表作为输出。代码中有什么错误。

[<filter object at 0x7fe7bdfff8d0>, <filter object at 0x7fe7a6eaaf98>, <filter object at 0x7fe7a6f08048>,

Answer 1

您忘了使用强制转换内部filter函数，list执行此操作时，代码按预期工作了:)

myList = [[123,0.0,345,0.0,0.0,0.0],
 [45,0.0,0.0,0.0],
 [67,8,0.0,5,6,7,0.0]]

#Cast inner filter into a list
myList = list(list(filter(lambda j:j!=0,myList[i])) for i in range(len(myList)))
print(myList)

输出将是

[[123, 345], [45], [67, 8, 5, 6, 7]]

同样，更简单的理解方式是使用列表理解

myList = [[123,0.0,345,0.0,0.0,0.0],
 [45,0.0,0.0,0.0],
 [67,8,0.0,5,6,7,0.0]]

#Using list comprehension, in the inner loop check if item is non-zero
myList = [ [item for item in li if item != 0] for li in myList ]
print(myList)

输出将是

[[123, 345], [45], [67, 8, 5, 6, 7]]