Parentheses are not required after the assert, del, elif, except, for,
if, in, not, raise, return, while, and yield keywords, and
using them unnecessarily impairs readability. They should therefore be omitted.
x = 1
while (x < 10):
print "x is now %d" % (x)
x += 1
x = 1
while x < 10:
print "x is now %d" % (x)
x += 1