python中集合与列表如何相互转换？

# 列表转集合(去重)

list1 = [6, 7, 7, 8, 8, 9]

set(list1)

# {6, 7, 8, 9}

s={1,2L,3.1,1,"hello",1+4j}

print s

print type(s)

li1=list(s)

print li1

print type(li1)

set([1, 2L, 3.1, (1+4j), 'hello'])

<type 'set'>

[1, 2L, 3.1, (1+4j), 'hello']

<type 'list'>