python中的元组

一.元组的定义

1.定义一个元组

users = ( 'tommy','harry','michael')
print users

 2.定义一个空元组

users = ()

3.当元组中只有一个元素时

users = ('tommy',)
print type(users)
users1 = (50)
print type(users1

 

二.元组的特性

1.索引与切片

allowUsers = ('root','xaut','hellp')
allowPasswd = ('123','456','789')

print allowUsers[0]               
print allowUsers[-1]
print allowUsers[1:]
print allowUsers[2:]
print allowUsers[:-1]
print allowUsers[::-1]    

 

2.重复与连接

allowUsers = ('root','xaut','hellp')
allowPasswd = ('123','456','789')

print allowUsers * 3                 ##重复显示

print allowUsers + ('123','456')   ##连接

 

3.成员操作符

allowUsers = ('root','xaut','hellp')
allowPasswd = ('123','456','789')

print 'westos' in allowUsers
print 'westos' not in allowUsers
print type(allowUsers)

 

三.元组的应用

1.变量交换数值

a = 1
b = 2
b,a = a,b
print a,b

 

或

a = 1
b = 2
b =(1,2)[0] a=(1,2)[1]
print a,b

 

2.打印变量值

name = 'student'
age = 10
t = (name,age)
print 'name: %s,age: %d' %(name,age)

 

3.给变量赋值

t = ('student',10,100)
name,age,score = t
print name,age,score

 

4.元组的排序

scores = (100,89,45,78,65)
scoresLi = list(scores)
scoresLi.sort()
print scoresLi

这种方法实际上是先把元组转换为列表再用列表的方法排序

 

 

 

或

scores = (100,89,45,78,65)
scores = sorted(scores)
print scores