CODEWITHSUNDEEP
pythonpandas
Ajay Chinni
Ajay Chinni

Reputation: 850

Pandas to check if value is NONE

I have a dataFrame

df = pd.DataFrame({'k':['a','b','c'],'v':[1,None,3]})

   k    v
0  a  1.0
1  b  NaN
2  c  3.0

I want to check if column k's b value is NaN or not

I have tried

if df['v'][df['k']=='b'] is None:
    print("yes")
else:
    print('no')

this gives output no

I have also tried

if df['v'][df['k']=='b'] == None:
    print("yes")
else:
    print('no')

and

if df['v'][df['k']=='b'].isna():
    print("yes")
else:
    print('no')

both give me this error

ValueError: The truth value of a Series is ambiguous. Use a.empty, a.bool(), a.item(), a.any() or a.all().

Upvotes: 1

Views: 2926

Answers (1)

Celius Stingher
Celius Stingher

Reputation: 18377

If, as long a you have a null value, you would want to return the True then use .any(). If you want all values to be Null (in this case it doesn't matter because there's a single value) then use .all():

if df[df['k']=='b']['v'].isna().any():
    print("yes")
else:
    print('no')

Output:

yes

Upvotes: 1

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