Why is the line crashing program when line is false?

[deanhystad]

If this relates to your earlier post you prevent any code that uses personnel from running if you don't set personnel. This is a bad pattern:

if a:
   b = 5
c = b * 2

Cannot use b because b may not be defined or may have the wrong value.
This is better

if a:
   b = 5
   c = b * 2
else:
   c = someothervalue