Transforming rows of DataFrame

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.

Getting ready

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:

• IfFinalis missing or less than 50, then the grade isfail
• IfFinalis greater than or equal to 50 but less than 75, and both Midterm and TakeHomeare 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...