004_013 Python 获取一个字典的子集

代码如下：

#encoding=utf-8print '中国'#获取一个字典的子集print '---列表推导'#不修改原来的字典 列表推导def sub_dict(somedict,somekeys,default=None):    return dict([(k,somedict.get(k,default)) for k in somekeys])dict1={1:2,3:4,6:7,9:10}somekeys=(1,9)print sub_dict(dict1,somekeys)print dict1#修改原来的字典 列表推导def sub_dict_remove(somedict, somekeys, default=None):    return dict([(k,somedict.pop(k,default)) for k in somekeys])print sub_dict_remove(dict1,somekeys)print dict1print '---生成器表达式'#不修改原来的字典 生成器表达式def sub_dict2(somedict,somekeys,default=None):    return dict((k,somedict.get(k,default)) for k in somekeys)dict1={1:2,3:4,6:7,9:10}somekeys=(1,9)print sub_dict2(dict1,somekeys)print dict1#修改原来的字典 生成器表达式def sub_dict_remove2(somedict, somekeys, default=None):    return dict((k,somedict.pop(k,default)) for k in somekeys)print sub_dict_remove2(dict1,somekeys)print dict1

打印结果如下：

中国
{1: 2, 9: 10}
{1: 2, 3: 4, 6: 7, 9: 10}
{1: 2, 9: 10}
{3: 4, 6: 7}
{1: 2, 9: 10}
{1: 2, 3: 4, 6: 7, 9: 10}
{1: 2, 9: 10}
{3: 4, 6: 7}