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K-Fold Cross-Validation Code
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K-Fold Cross-Validation Code

MediumPython

Problem

Can you write a code snippet to perform k-fold cross-validation?

Implement k_fold_split(n_samples, k, shuffle, seed) using only Python's standard library. Return k pairs of training and validation index lists, with every sample used exactly once for validation. Validation folds should be as balanced as possible, and shuffling must be reproducible when a seed is provided. For example, n_samples = 5, k = 2, shuffle = False returns validation folds of sizes 3 and 2.

Constraints

  • 1 <= n_samples <= 10000
  • 2 <= k <= n_samples
  • 0 <= seed <= 10^9
  • shuffle is a boolean
  • Training and validation indices in each split must be disjoint
  • Every sample must appear in exactly one validation fold

Function Signature

def k_fold_split(n_samples, k, shuffle, seed):
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