Boolean false filter in update selection query

General Usage
,
1

Hello,

Am trying to update values in a dataframe as follows:

df[
    (
        df[!, :country] .== country 
        && !df[!, :bool]
    ),
    :value
] = value

However I receive error that non-boolean value is used in a boolean context.

Above works if I use df[!, :bool] (condition as true).

How can I perform above query using false condition in statement?

Thanks

2

Can you share a sample of df? That would make it easier to diagnose. I.e. a “minimum working example”

3

Is this what you are looking for:

julia> using DataFrames

julia> df = DataFrame(country = ["A", "B", "A", "A"], bool = [true, true, false, true], value = zeros(4))
4×3 DataFrame
│ Row │ country │ bool │ value   │
│     │ String  │ Bool │ Float64 │
├─────┼─────────┼──────┼─────────┤
│ 1   │ A       │ 1    │ 0.0     │
│ 2   │ B       │ 1    │ 0.0     │
│ 3   │ A       │ 0    │ 0.0     │
│ 4   │ A       │ 1    │ 0.0     │

julia> df[(df.country .== "A") .& df.bool, :value] = 1
1

julia> df
4×3 DataFrame
│ Row │ country │ bool │ value   │
│     │ String  │ Bool │ Float64 │
├─────┼─────────┼──────┼─────────┤
│ 1   │ A       │ 1    │ 1.0     │
│ 2   │ B       │ 1    │ 0.0     │
│ 3   │ A       │ 0    │ 0.0     │
│ 4   │ A       │ 1    │ 1.0     │
1 Like
4

Yes this is what I am looking for. Thank you!

5

For the negation you can use

df[(df.country .== "A") .& (df.bool .!= true), :value] = 1
1 Like
6

Yes makes sense. Thanks again

2 Likes