Numpy isnan（）在浮点数组上失败（适用于pandas数据框）

我有一个浮点数数组（一些正常数字，一些nans），它们是从对熊猫数据框的应用中得出的。

由于某种原因，numpy.isnan在此数组上失败，但是，如下所示，每个元素都是浮点数，numpy.isnan在每个元素上正确运行，变量的类型肯定是numpy数组。

这是怎么回事？！

set([type(x) for x in tester]) Out[59]: {float}

tester Out[60]: array([-0.7000000000000001, nan, nan, nan, nan, nan, nan, nan, nan, nan, nan, nan, nan, nan, nan, nan, nan, nan, nan, nan, nan, nan, nan, nan, nan, nan, nan, nan, nan, nan, nan, nan, nan, nan, nan, nan, nan, nan, nan, nan, nan, nan, nan, nan, nan, nan, nan, nan, nan, nan, nan], dtype=object)

set([type(x) for x in tester]) Out[61]: {float}

np.isnan(tester) Traceback (most recent call last):

File " ", line 1, in np.isnan(tester)

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''

set([np.isnan(x) for x in tester]) Out[65]: {False, True}

type(tester) Out[66]: numpy.ndarray 问题来源于stack overflow