One-hot encoding. One-hot-encoding represents the 86 peptide sequence in an n-dimensional vocabulary such that 87 each dimension encodes the presence of a particular amino 88 acid in a particular position (denoted with a 1 if present). 89 peptidy assigns a pre-defined position to each amino 90 acid and post-translational modification in the vocabulary, 91 and represents the peptide sequences accordingly. This 92 function returns a L × 28 dimensional matrix by default, 93 where each column encodes the existence of an amino acid 94 or a post-translation, for a total of 28 elements in the dic-95 tionary.