Twig coding challenge

This project consists of two files: splitter.py, which contains the method split_array to satisfy the requirements of the challenge, and test_splitter.py, which contains unit tests for this method.

How to execute

One way to execute the code:

1. Open an interactive Python shell from this directory.
2. Enter from splitter import split_array
3. Call the above method, with a one-dimensional array as its first argument and a positive integer as its second.

To run the unit tests:

1. Ensure Pytest is installed on your machine.
2. From a terminal in this directory, run pytest.

Implementation notes

I decided to use Python for this task, as it requires very little setup to create a working project with concise, readable code.

For the main task, I decided to use a list comprehension to build the list of sub-arrays, as this seemed the clearest way to structure the logic.

The method checks the types of the arguments provided to it, as per the conditions given in the challenge specification, and that the number of sub-arrays to be created is a positive integer.

Edge case

When writing the solution, I came across an edge case that produces a somewhat counter-intuitive result for my solution, though I could not see that it violated the conditions put forth by the challenge.

The effect produced is that the resulting list of sub-arrays includes 1 or more empty arrays, i.e.

split_array([1,2,3,4], 3) = [[1,2],[3,4],[]]

This edge case arises when the following condition is true for an array of length x and a number of sub-arrays y:

(y / x) % 1 < 0.5

This is because my solution uses "ceiling division" to find the size of a sub-array, i.e. it always rounds up, otherwise not every element in the original array would be included in the list of sub-arrays produced by the method.

Unsure of whether or not this is the desired output, I decided to leave the solution as-is, include a unit test to highlight the edge case and document it here.