def read_molecule(reader):
    line=reader.readline()
    if not line:
        return None
    while not line.startswith('COMPND'):
        line=reader.readline()

    key, name = line.split()
    molecule=[name]
    line = reader.readline()
    while not line.startswith('END'):
        key, num, atom_type, x, y, z = line.split()
        molecule.append([atom_type, x, y, z])
        line = reader.readline()


    return molecule

def read_all_molecules(reader):
    result = []
    reading=True
    while reading:
        molecule = read_molecule(reader)
        if molecule:
            result.append(molecule)
        else:
            reading=False

    return result





if __name__ == '__main__':
    molecule_file = open('PDB.txt', 'r')
    molecules = read_all_molecules(molecule_file)
    print(molecules)