python元字典
字典(dictionary)是除列表以外python之中最灵活的内置数据结构类型。列表是有序的对象结合，字典是无序的对象集合。
两者之间的区别在于：字典当中的元素是通过键来存取的，而不是通过偏移存取。
字典用”{ }”标识。字典由索引(key)和它对应的值value组成。
#!/usr/bin/python
# -*- coding: utf-8 -*-
dict = {}
dict[‘one’] = “this is one”
dict[2] = “this is two”
tinydict = {‘name’: ‘john’,’code’:6734, ‘dept’: ‘sales’}
print dict[‘one’] # 输出键为’one’ 的值
print dict[2] # 输出键为 2 的值
print tinydict # 输出完整的字典
print tinydict.keys() # 输出所有键
print tinydict.values() # 输出所有值
输出结果为：
this is one this is two {‘dept’: ‘sales’, ‘code’: 6734, ‘name’: ‘john’} [‘dept’, ‘code’, ‘name’] [‘sales’, 6734, ‘john’]
python成员运算符
除了以上的一些运算符之外，python还支持成员运算符，测试实例中包含了一系列的成员，包括字符串，列表或元组。
以下实例演示了python所有成员运算符的操作：
#!/usr/bin/python
a = 10
b = 20
list = [1, 2, 3, 4, 5 ];
if ( a in list ):
print “line 1 – a is available in the given list”
else:
print “line 1 – a is not available in the given list”
if ( b not in list ):
print “line 2 – b is not available in the given list”
else:
print “line 2 – b is available in the given list”
a = 2
if ( a in list ):
print “line 3 – a is available in the given list”
else:
print “line 3 – a is not available in the given list”
以上实例输出结果：
line 1 – a is not available in the given list
line 2 – b is not available in the given list
line 3 – a is available in the given list