Performing a transformation on a set of columns in a DataFrame
object is one of the most common operations. In this recipe, we describe how you can perform complex transformations on rows in DataFrame
.
In this recipe, we use the grades
dataset, which we have already used in the Working with categorical data recipe.
Assume there are the following grading rules in this course:
- If
Final
ismissing
or less than 50, then the grade isfail - If
Final
is greater than or equal to 50 but less than 75, and bothMidterm
andTakeHome
are missing or less than 50, then the grade isfail - In all other cases, the grade ispass
Make sure you have the CSV.jl
and DataFrames.jl
packages installed. If they are missing, add them using the following commands:
julia> using Pkg julia> Pkg.add("DataFrames") julia> Pkg.add("CSV")
Before we begin, start the Julia command line and load the grades.csv
file into a data frame, using the following commands:
julia> using CSV, DataFrames...