The Group command creates or updates a "group" object. The grouped objects are collected underneath a + sign in the object tree (see images) in the Pymol Internal Gui.
Group is tremendously helpful with multi-state or multi-structure sessions. Wildcards work great, for example:
# put all of objState into the group "ensemble". group ensemble, objState*
group name, members, action
Creating, opening and closing
group efHand, 1cll 1ggz 1sra # allow addition and removal from the group group efHand, open # disallow addition/removal from the group group efHand, close
More advanced usage of groups and naming
# names with dots are treated special set group_auto_mode, 2 # load the example protein load $TUT/1hpv.pdb, 1hpv.other # create the new entry called ".protein" in group 1hpv extract 1hpv.protein, 1hpv.other and polymer # create ".ligand in the 1hpv group extract 1hpv.ligand, 1hpv.other and organic # supports wildcards show sticks, *.ligand hide lines, *.protein show surface, *.protein within 6 of *.ligand show lines, byres *.protein within 4 of *.ligand set two_sided_lighting set transparency, 0.5 set surface_color, white # Also, to lexicographically sort the names in the control panel: order *, yes
Group objects can usually be used as arguments to commands. It can be processed as a group or as a selection, in which case all the atoms from all objects in the group will be used.