如何检查包含NaN的列表

我认为这是有道理的,因为你numpy通过明星导入间接进入范围.

>>> import numpy as np
>>> [0.0,0.0]/0
Traceback (most recent call last):
  File "<ipython-input-3-aae9e30b3430>", line 1, in <module>
    [0.0,0.0]/0
TypeError: unsupported operand type(s) for /: 'list' and 'int'

>>> [0.0,0.0]/np.float64(0)
array([ nan,  nan])

当你做到了

from matplotlib.pylab import *

它拉进来了numpy.sum:

>>> from matplotlib.pylab import *
>>> sum is np.sum
True
>>> [0.0,0.0]/sum([0.0, 0.0])
array([ nan,  nan])

您可以通过标识测试此 nan对象(nan通常不是唯一的)在列表中,但如果您在其中尝试array它似乎通过相等性进行测试,并且nan != nan:

>>> nan == nan
False
>>> nan == nan, nan is nan
(False, True)
>>> nan in [nan]
True
>>> nan in np.array([nan])
False

你可以使用np.isnan:

>>> np.isnan([nan, nan])
array([ True,  True], dtype=bool)
>>> np.isnan([nan, nan]).any()
True

您应该使用该math模块。

>>> import math
>>> math.isnan(item)