How can I check for NaN values?

Question

float(\'nan\') results in Nan (not a number). But how do I check for it? Should be very easy, but I cannot find it.

Answer 1

For nan of type float

>>> import pandas as pd
>>> value = float(nan)
>>> type(value)
>>> 
>>> pd.isnull(value)
True
>>>
>>> value = 'nan'
>>> type(value)
>>> 
>>> pd.isnull(value)
False