clg4 - 5 months ago 49

Python Question

I have a Pandas dataframe

`df`

`A B`

1 1 [a,b,d,d]

2 6 [,1,4,d,g]

3 a [w,1,NaN,x,y,2]

I need to remove the blank in row 2, and the NaN in row 3 to get:

`A B`

1 1 [a,b,d,d]

2 6 [1,4,d,g]

3 a [w,1,x,y,2]

I think applying some kind of lambda list comprehension?

`df.B=df.B.apply(lambda x: x if x not in ['',np.NaN])`

but not working...

Answer

You need to work on your comprehension skills :)

```
import numpy as np
df = pd.DataFrame([
[1, ['a','b','d','d']],
[6, ['',1,4,'d','g']],
['a', ['w',1,np.nan,'x','y',2]]
], columns=['A', 'B'])
df.B.apply(lambda l: [x for x in l if x not in ['', np.nan]])
```

where `l`

is the current list and `x`

are elements of `l`

.