def _get_codons_from(codons_dict):
    """Extract all codons from dictionary in a single list.

    Parameters
    ----------
    codons_dict : dict

    Returns
    -------
    list


    """
    all_codons = list()
    for  codons_list in codons_dict.values():
        all_codons.extend(codons_list)

    return all_codons