Undefined variable

[noelb6]

So I just started python today for a class, and I defined my variables. But when I run the program it says that the variable isn't defined.
How can I fix this?

[Tony]

Likely a scope issue. A variable with the same name might be defined elsewhere, but it's not visible from where you are trying to use it. E.g. code inside one function doesn't see local variables defined in another function.

[noelb6]

it says "line 15, in <module>
while i == 0:
NameError: name 'i' is not defined"

But i have it define before that and i tried erasing it and it still didnt work

[Tony]

in the little amount of code that you've shared, I don't see you defining that variable.

[noelb6]

That;s what the error said
But I defined i = 0 before

[Tony]

post the code.

[noelb6]

def main():
print("This program prints out the 978th prime number")
x = 1
p = 0
z = 1
i = 0
while p < 978:
while i == 0:
if x % z == 0:
i = 1
if z == x/2:
i = 2
else:
i = 0
z = z + 1
if i == 1:
print x, "is a composite"
else:
print x, "is a prime"
p = p + 1

[noelb6]

main()

[Tony]

Python is indentation sensitive; they define blocks.

code:

def main():     print("This program prints out the 978th prime number")     x = 1     p = 0     z = 1     i = 0 while p < 978:  while i == 0:     if x % z == 0:         i = 1     if z == x/2:         i = 2     else:         i = 0         z = z + 1     if i == 1:         print x, "is a composite"     else:         print x, "is a prime"         p = p + 1

i is defined and is local to main().

your while loops are outside of main.

code inside while loops can't see what's defined inside of main.

[noelb6]

how do i fix that?

[Tony]

Have them all in the same scope http://en.wikipedia.org/wiki/Scope_(computer_science)

The easiest way would be to simply place your while loops inside of main().

[noelb6]

That worked, thank you.
Now time to fix my loops x.x