Explation:

Question: "Python:
>>> LINE A
>>> LINE B
>>> LINE C
False
>>> LINE A; LINE B; LINE C
True

what are the lines? nothing stateful allowed & no __methods."
(https://twitter.com/akaptur/status/395252265117687808).

My answer:
The given example. It relies on the fact that if the three lines are written together,
then they become part of the body of the for loop, whereas separated the for loop only
has the single statement in it. This is used to have variable (x) set to either 0 or 2
at the end of the loop. Since the print statement will be executed twice if it's inside
the loop (the loop body executes twice), Nothing gets printed if x is 1, which happens
during the first iteration when the lines are written together.

The "x = n or x-1" allows initializing x on the first iteration - because n is -1, it
will be assigned -1. On the second iteration, n == 0 == False, so the statement will
assign x-1 to x.


Executing in Ipython I get:
In [142]: for n in range(-1,1):x=n or x-1;

In [143]: x+=2;

In [144]: sys.stdout.write("" if x == 1 else ("False" if x == 0 else "True"))
False
In [145]: for n in range(-1,1):x=n or x-1;x+=2;sys.stdout.write("" if x == 1 else ("False" if x == 0 else "True"))
True
In [146]: 

gistfile1.py

for n in range(-1,1):x=n or x-1;x+=2;sys.stdout.write("" if x == 1 else ("False" if x == 0 else "True"))



for n in range(-1,1):x=n or x-1;
x+=2;
sys.stdout.write("" if x == 1 else ("False" if x == 0 else "True"))