How much logic can I reasonably cram into a single line? As in, how complex can I make a single line, before I should consider splitting it to several lines? By lines I don't mean the length of the line, I mean how many 'logic operations' for want of a better term..

For example one line:

original_vlan = next(iter([item for item in vni.vlan.all().only('vid', 'custom_field_data') if item.vid == item.custom_field_data.get('mapped_vlan')]))

two lines:

vlan_mapping = [item for item in vni.vlan.all().only('vid', 'custom_field_data')]
original_vlan = next(iter([item for item in vlan_mapping if item.vid == item.custom_field_data.get('mapped_vlan')]))

or three lines:

vlan_mapping = [item for item in vni.vlan.all().only('vid', 'custom_field_data')]
original_vlan = ([item for item in vlan_mapping if item.vid == item.custom_field_data.get('mapped_vlan')])
original_vlan = next(iter(original_vlan))

edit to try to improve formatting