条件循环一些小知识点

''' Created on 2011-9-28 @author: xgzhao ''' s = 'abcdefg' print s[::-1] #reverse print s[::2] # just like a?x:y in Java, in Python is: x if c else y x, y = 4, 3 smaller = x if x<y else y print smaller #about range print range(2, 19, 2) print [x**2 for x in range(6)] print eval("222") #set in Python s = set('cheershop') print s t = set('zhaoxin') # | to union two sets print s|t # & print s&t print s-t