def read_sequence(filepath, labels=True):
    """
    Return the list of protein sequences and cleavage sites from datapath.

    The data file must strictly follow the following pattern:
    - first line is a description of the sequence
    - second line is the sequence itself
    - third line is a list of chars S, C, M

    Example:
    52 AGP_ECOLI      22 GLUCOSE-1-PHOSPHATASE PRECURSOR (EC 3.1.3.10) (G1PASE).
    MNKTLIAAAVAGIVLLASNAQAQTVPEGYQLQQVLMMSRHNLRAPLANNGSV
    SSSSSSSSSSSSSSSSSSSSSSCMMMMMMMMMMMMMMMMMMMMMMMMMMMMM
    """
    protein_sequence = []
    cleavage_site = []

    # Loop condition conveniently discards the description lines
    with open(filepath, 'r') as f:
        while f.readline() is not '':
            # Slicing with :-1 to discard "\n" character
            protein_sequence.append(f.readline()[:-1])
            if labels:
                cleavage_site.append(f.readline()[:-1])

    return protein_sequence, cleavage_site