How do I save my dictionary as a .csv (or excel) file?

New to Julia
1

I have a dictionary, which I want to save to an excel or csv file with keys in one column and the entries in another. The keys are strings and the entries are float64s. I thought about converting my dictionary to a DataFrame but I am not sure if this type is supported in Julia or how to convert if it is, or even how to save a dataframe as csv. Can dictionaries be saved as csv files directly?

Thanks

2

This is easily done with the CSV package (If you don’t have it, run Pkg.add(“CSV”) in your REPL)

using CSV
test = Dict("a"=>1, "b"=>2, "c"=>3)
CSV.write("test.csv", test)

You can add a file-path like this: “/Users/your/custom/location/test.csv”

3

If you want to save in .xlsx:

using XLSX
x      = Dict("a"=>1.0, "b" => 2.0)  
fid    = XLSX.openxlsx("df.xlsx", mode="w")
header = ["keys";"values"]
data   = [[collect(keys(x))];[collect(values(x))]]

XLSX.writetable("df.xlsx", data,header)

https://felipenoris.github.io/XLSX.jl/stable/tutorial/

1 Like
4

Thanks, that works. Is there a way to specify headers? I tried CSV.write("File.csv",VariableName,["Column1Name";"Column2Name]) but I got a Method error.

5

Thanks! I think csv would be most convenient however. That being said the header argument you have specified doesn’t seem to work for csv.write :frowning:

6

The example is only for Excel files and it’s using the XLSX package.
If you want to use CSV to write .csv files as in @TheLateKronos example, you could define your header as a comma delimited string, write that line to csv, and then write your test dictionary.

7

It seems you can specify custom column names when reading CSV’s, but I also just get the same error when I try to specify a vector of strings as column names. The best I can think of is to have the keyword argument append=true, which makes it so that column names are not written. Then you can add them yourself manually.

Alternatively find a way to write it to a dataframe with the column names you want, and save that

8

Hello guys, still have a question:

how to read this .csv (or .xlsx) file into a variable with the type of Vector{Dict{}}?