index of non “NaN” values in Pandas

Question

From Pandas data frame, how to get index of non \"NaN\" values?

My data frame is

    A    b     c
0   1    q1    1
1   2    NaN   3
2   3    q2    3
         


        

Answer 1

Just filter them

In [62]:

df['b'].notnull()

Out[62]:
0     True
1    False
2     True
3     True
4     True
Name: b, dtype: bool
In [63]:

df[df['b'].notnull()]
Out[63]:
   A   b   c
0  1  q1   1
2  3  q2   3
3  4  q1 NaN
4  5  q2   7

Answer 2

DataFrames have a dropna method:

import pandas
import numpy

d = pandas.DataFrame({'A': [1, 2, 3, numpy.nan], 
                      'b': [1, 2, numpy.nan, 3],
                      'c': [1, numpy.nan, 2, 3]})
d.dropna(subset=['b'])