Pandas - check if ALL values are NaN in Series
PythonPandasNullNanSeriesPython Problem Overview
I have a data series which looks like this:
print mys
id_L1
2 NaN
3 NaN
4 NaN
5 NaN
6 NaN
7 NaN
8 NaN
I would like to check is all the values are NaN.
My attempt:
pd.isnull(mys).all()
Output:
True
Is this the correct way to do it?
Python Solutions
Solution 1 - Python
Yes, that's correct, but I think a more idiomatic way would be:
mys.isnull().all()
Solution 2 - Python
This will check for all columns..
mys.isnull().values.all(axis=0)
Solution 3 - Python
if df['col'].count() > 0:
then ...
This works well but I think it might be quite a slow approach. I made the mistake of embedding this into a 6000-times loop to test four columns - and it's brutal, but I can blame the programmer clearly :)
Obviously, don't be like me. Always: Test your columns for all-null once, set a variable with the yes - "empty" or no - "not empty" result - and then loop.