If you delete a variable will everything you've done previously with the variable (before you changed it) change as well?

Answer 1

Nope wont, kind of reassigning it

Answer 2

python is unlike c or other languages,.. where a value get assigned to a variable.. in python values are considered as objects and the variables get referred to the objects.. instead of assignment ..
for better explanation, plz look at http://python.net/~goodger/projects/pycon/2007/idiomatic/handout.html#other-languages-have-variables

Answer 3

it depend on assigning and what do you use ?
example:
a = 5
b = 6
c = a + b
print(c)
del a
#print(a+b) #<--- if you use this, it will find a
#then NameError occur because you already del a
#print(c) #<--- if you use this , it will call c