while True:
x = int(raw_input("Enter an integer: "))
if x == 0 :
print("Zero, exiting")
break
elif x < 0:
print("Negative integer")
else:
print("Positive integer")
Example 2
Read input, integer N between 1 and 20.
For all non-negative integer less than N, print the square of the integer
N=int( raw_input() )
if N>=1 and N<=20 :
i=0
while i<N :
v=i*i
i=i+1
print v