Hands-On Design Patterns and Best Practices with Julia

Preparing data for the example

To follow the subsequent code for this pattern, we can prepare some test data. Before you run the code here, make sure that you have enough disk space for the test data. You will need approximately 22 GB of free space.

Rather than putting 100,000 files in a single directory, we can split them into 100 sub-directories. So, let's just create the directories first. A simple function is created for that purpose:

function make_data_directories()    for i in 0:99         mkdir("$i")     endend

We can assume that every security is identified by a numerical index value between 1 and 100,000. Let's define a function that generates the path to find the file:

function locate_file(index)    id = index - 1    dir = string(id % 100) joinpath(dir, ...