questions about of writing python scripts

[ed]

Hi I have a question regarding writing python scripts..
for large program written i python,, One thing i notice is it needs to
run to the specifc piece of code i order to detect error. let's say
the valaue is assigned to a wrong variables, I cannot know in advance,

say I have
b = 1 (defined way earlier)
if x == 1:
   a = b
else:
   a = c
which a to be used as interger later on.

x being passed in eariler.
since b is deinfed I can assign to it,

but c is floating and has not value and a got assgined to it.  ... in
other compiation lang, this type of error will be caught in
compilaiton time, but I can't using python..  is ther any utility or
way to catch this type of error way ahead?
thankx