%%的一个应用

 1 """
 2 This script illustrate the usage of escape symbol %%. In general, it is used in mutil-formatted string. when a string is
 3 formatted , %% can escape a % so that just one remains for the final formatting operation at the end.
 4 """
 5 a='%s%%s'%'yjs' 
 6 print(a)    # print a as '%syjw'
 7 b=a%'jjj'   # format variable a again
 8 print(b)    # print b as 'jjjyjw'
 9 #******************
10 a='%%s%s'%'yjw'
11 print(a)
12 b=a%'jjj'
13 print(b)