결측치 확인 (isna, isnull

col  = ['col1','col2','col3','col4']
row  = ['row1','row2','row3']
data = [[1,2,pd.NA,4],
        [np.nan,6,7,8],
        [9,10,11,None]]
df = pd.DataFrame(data,row,col)
>>
      col1  col2  col3  col4
row1   1.0     2  <NA>   4.0
row2   NaN     6     7   8.0
row3   9.0    10    11   NaN

 

1)isna / isnull

>결측값이면 True반환

print(df.isna())
>>
       col1   col2   col3   col4
row1  False  False   True  False
row2   True  False  False  False
row3  False  False  False   True

 

2)notna / notnull 

>결측값이면 False반환

 

print(df.notna())
>>
       col1  col2   col3   col4
row1   True  True  False   True
row2  False  True   True   True
row3   True  True   True  Fals