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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def pack_sidechains(pdb, sequence, path=False):
 """Packs sidechains onto a given PDB file or string. Parameters pdb : str PDB string or a path to a PDB file. sequence : str Amino acid sequence for SCWRL to pack in single-letter code. path : bool, optional True if pdb is a path. Returns ------- scwrl_pdb : str String of packed SCWRL PDB. scwrl_score : float Scwrl packing score. """

    scwrl_std_out, scwrl_pdb = run_scwrl(pdb, sequence, path=path)
    return parse_scwrl_out(scwrl_std_out, scwrl_pdb)