从列表中删除 nan - Python

Question

我试图从列表中删除 'nan'，但它拒绝去。我已经尝试过 np.nan 和 'nan'。

这是我的代码：

ztt = []
for i in z:
    if i != 'nan':
        ztt.append(i) 
ztt

或者：

ztt = []
for i in z:
    if i != np.nan:
        ztt.append(i) 
ztt

我仍然得到输出：

[[46.0, 34.0, 32.0, 40.0, 34.0, 29.0, 38.0, 39.0, 45.0, 32.0, 28.0, 43.0],
 [32.0, 30.0, 67.0, 66.0, 28.0, 19.0, 39.0, 32.0, 51.0, 28.0, 20.0, 36.0],
 [29.0, 24.0, 37.0, 31.0, 32.0, 34.0, 28.0, 31.0, 28.0, 33.0, 28.0, 39.0],
 [27.0, 29.0, 35.0, nan, nan, nan, nan, nan, nan, nan, nan, nan]]

有谁知道出了什么问题？

Answer 1

for i in z:
    if not math.isnan(i):
        ztt.append(i)

Answer 2

ztt = []
for z_i in z:
    row = []
    for z_ij in z_i:
        if math.isnan(z_ij):
            row.append(z_ij)
        # If you want to replace with, for example, 0:
        # else:
        #     row.append(0)
    ztt.append(row)

或者，使用嵌套列表理解：

ztt = [[z_ij for z_ij in zi if math.isnan(z_ij)] for z_i in z]

顺便说一句，如果你使用 NumPy，你可能可以这样做：

import numpy as np

ztt =[value[~np.isnan(value)] for value in z]