## Chain.atom_file_and_code() — get suitable names for this chain

`atom_file_and_code(filename)`

> Given a model filename, this returns suitable atom_file and align_code values for this chain, for example for giving to Chain.write(). Path names are stripped, and duplicate chain IDs are handled.

> For example, a model filename of `/home/user/test.pdb` may return `test` for atom_file and `testA` for align_code when called for the `A` chain.

Example: See Chain.filter() command.