I finally found the missingstring and missingstrings parameters for CSV.File
It completely solves the problem with:
df = CSV.File(“filename.csv”, missingstring=“NA”) |> DataFrame
if there are more than one string replacing the missing values, it’s:
df = CSV.File(“filename.csv”, missingstrings=[“string1”, “string2”) |> DataFrame
hope this can help someone else coming from Python