Julia 1.0 Programming Complete Reference Guide

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Julia comes with excellent facilities for reading and storing data out of the box. Given its focus on data science and scientific computing, support for tabular-file formats (CSV, TSV) is first class.

Let's extract some data from our initial dataset and use it to practice persistence and retrieval from various backends.

We can reference a section of a DataFrame by defining its bounds through the corresponding columns and rows. For example, we can define a new DataFrame composed only of the PetalLength and PetalWidth columns and the first three rows:

julia> iris[1:3, [:PetalLength, :PetalWidth]] 3×2 DataFrames.DataFrame │ Row │ PetalLength │ PetalWidth │ ├─────┼─────────────┼────────────┤ │ 1 │ 1.4 │ 0.2 │ │ 2 │ ...