Fix FileNotFoundError when custom template filenames use upper-case PDB codes or extensions

[crfield18]

File changed: AlphaFold2.ipynb

Issue

AlphaFold's _get_pdb_id_and_chain (alphafold/data/templates.py) always lowercases the 4-character PDB code before looking up the template file on disk. The notebook saves uploaded custom templates using their original casing:

for fn in uploaded.keys():
    os.rename(fn,os.path.join(custom_template_path,fn))

So uploading e.g. 5HBF.cif causes:

FileNotFoundError: [Errno 2] No such file or directory: '<jobname>/template/5hbf.cif'

Fix

Normalize the filename's stem and extension to lower case before saving:

for fn in uploaded.keys():
    base, ext = os.path.splitext(fn)
    dest_fn = base.lower() + ext.lower()
    os.rename(fn, os.path.join(custom_template_path, dest_fn))
    print(f"saved template: {fn} -> {dest_fn}")

Handles .pdb/.cif uploads in any casing (5HBF.CIF, 5hbf.PDB, etc.).