tuple-1

tuple即元组

简介和基本的属性

# -*- coding: utf-8 -*-
"""
Created on Tue Jun 03 20:39:19 2014

@author: Administrator
"""

"""
' tuple是一种集合类型(collection type),可构建简单对象的组别
' 功能同list，但是tuple不可以修改，用()而不是[]构建，不支持方法调用
' 但是其大多数属性同list
' tuple是任意对象的有序集合
' tuple通过偏移量进行访问
' tuple是分类不可变的序列(of the category immutable sequence)
' tuple是固定长度、异质性、可随意嵌套
' tuple是对象引用的数组
"""

# an empty tuple demo
# 用括号可提高代码的可读性
tpl_1 = ()
print tpl_1

# A one-item tuple
tpl_2 = (0,)

print tpl_2
print type(tpl_2)

# an integer
x = (40)

print x
print type(x)

# a four-item tuple
tpl_3 = (0,'Ni',2,3)
print tpl_3

# another four-item tuple
tpl_4 = 0,'Ni',2,3
print tpl_4

# nested tuples
tpl_5 = ('abc',('def','ghi'))
print tpl_5

# index, index of index, slice and length
print tpl_3[2]

print tpl_4[1][1]

print tpl_3[1:3]

print len(tpl_5)

# concatenate
print tpl_2 + tpl_3

print (1,2) + (3,4)

# repeat
print tpl_3 * 3

print (1,2) * 3

# iteration, membership
for item in tpl_4:
    print item * 2

if('spam' in tpl_4):
    print 'spam is in tpl_4'
else:
    print 'spam is not in tpl_4'