Editing Flatten obj (section)

= Description =

The <code>flatten_obj</code> python script combines multiple objects or states into a single object,
renaming chains where required.

This is particularly useful for dealing with biological assemblies, which are
loaded as multi-state objects when fetched using <code>[[fetch]] PDBID, type=pdb1</code>. It
can also be used as a quick way to combine multiple objects without causing
collisions between chain identifiers.

The command re-letters chains to avoid collisions. Older versions of PyMOL
restrict the chain id to a single character, so the script will fail for
assemblies with >62 chains. With more recent versions, this problem is solved
with multi-character chain IDs. Several options are available for how
re-lettering should occur.