###集合是无序的，不重复的元素集，类似数学中的集合，可进行逻辑运算和算术运算。
#无序 不重复
#set([list])
s=set(['a','b','c']) #集合对象s
print "集合s的长度",len(s)
print 'a' in s
print 'd' not in s
s1=set([1,2,3,4,5])
s2=set([1,2,3,4,5,6,7])
print "s1是否s2的子集:",s1.issubset(s2),"子集:等价于s1<=s2" #子集
print "s1是否s2的超集:",s1.issuperset(s2),"超集:等价于s1>=s2" #超集
s=set([1,2,3,4,5,6,7,8,9,10])
u=set([4,5,6,9,11,12,13,14,15])
print "s和u的并,等价于s|u:",s.union(u) #并集
print s|u
print "s和u的交,等价于s&u:",s.intersection(u) #交集
print s&u
print s.difference(u) #集合的差 即:s中有的并且u中没有的
print s-u
print u-s
print s.symmetric_difference(u) #集合的异或 即:s|u - s&u
print s^u
#!/usr/bin/python
# -*- coding: UTF-8 -*-
#用集合删除重复项
distances={10.6,11,8,10.6,"two",7}
print type(distances) #distance 为集合对象
print distances
for x in distances:
print x
mylist=[10.6,11,10.6,17.6,17.6,17.6]
myset=set(mylist)
print mylist
print myset
