python check if value is nan code example

Example 1: check if a value in dataframe is nan

#return a subset of the dataframe where the column name value == NaN 
df.loc[df['column name'].isnull() == True]

Example 2: python test is nan

math.isnan(n)

Example 3: check if something is nan python

import math
print math.isnan(float('NaN'))OutputTrue
print math.isnan(1.0)OutputFalse

Example 4: check if value is NaN

Number.isNaN(123)

Example 5: check is string is nan python

>>> pd.isnull(None)
True

Example 6: python checking if something is equal to NaN

# Test to see if it is equal to itself
def isNaN(num):
    return num != num