python - 如何从包含字符串条目的列表列表中删除 NaN？

Question

我正在尝试从列表列表(带有字符串条目)中删除所有 nans，我的数据如下:

[['beer', 'nuts', nan], 
['beer', 'butter', 'apple'], 
['beer', 'nuts', 'cheese'], 
['beer', 'bananas', nan], 
['beer', 'nuts', 'apple']]

我想得到这个结果:

[['beer', 'nuts'], 
['beer', 'butter', 'apple'], 
['beer', 'nuts', 'cheese'], 
['beer', 'bananas'], 
['beer', 'nuts', 'apple']]

我试过从(How to remove nan's from list of lists? [duplicate] 和 How to delete [NaN] from a list of lists?)中得到答案，即:

import math
nan = float('nan')

store_data_list = [[x for x in y if not math.isnan(x)] for y in store_data_list] #remove nans from list of lists

#AND

store_data_list = [xs for xs in store_data_list if not any(math.isnan(x) for x in xs)]

#AND

store_data_list = [[x for x in y if not np.isnan(x)] for y in store_data_list]

两者在我的实例中似乎都不起作用。我收到错误:

TypeError: must be real number, not str

TypeError: ufunc 'isnan' not supported for the input types, and the inputs could not be safely coerced to any supported types according to the casting rule ''safe''

谁能指出我做错了什么

Answer 1

一种选择是将项目与其自身进行比较(这对于 nan 是错误的)

nan = float('nan')
data = [['beer', 'nuts', nan], 
        ['beer', 'butter', 'apple'], 
        ['beer', 'nuts', 'cheese'], 
        ['beer', 'bananas', nan], 
        ['beer', 'nuts', 'apple']]
[[i for i in j if i == i] for j in data]

给予

[['beer', 'nuts'],
 ['beer', 'butter', 'apple'],
 ['beer', 'nuts', 'cheese'],
 ['beer', 'bananas'],
 ['beer', 'nuts', 'apple']]