Python探索记(13)——字典Dictionary

# @Time    : 2017/7/6 20:36# @Author  : 原创作者：谷哥的小弟# @Site    : 博客地址：http://blog.csdn.net/lfdfhl# @DESC    : Dictionary'''字典的每个元素由两部分组成即键和值可依据键查询其对应的值，如person['name']获取name对应的值亦可使用get()方法,假若该键不存在则返回默认值'''person={'name':'谷哥的小弟','age':25,'address':'china'}print('name=',person['name'])print('age=',person['age'])print('address=',person['address'])gender=person.get('gender','男')print('gender=',gender)print('= '*20)'''利用items()即可获取字典所有元素利用keys()获取字典中的所有key利用values()获取字典中的所有value利用in判断key是否在字典中；如果在则返回True，否则返回False'''person={'name':'谷哥的小弟','age':25,'address':'china'}items=person.items();for item in items:    print('字典中的item=',item)keys=person.keys()for key in keys:    print('字典中的key=',key)values=person.values()for value in values:    print('字典中的value=',value)result='gen' in personprint('result=',result)print('= '*20)'''利用len()获取字典中元素个数'''person={'name':'谷哥的小弟','age':25,'address':'china'}count=len(person)print('count=',count)print('= '*20)'''修改字典中的元素的值'''person={'name':'谷哥的小弟','age':25,'address':'china'}person['age']=27print('修改后的age=%i'%person['age'])print('= '*20)'''往字典中添加元素示例如下：往字典中添加gender=male'''person={'name':'谷哥的小弟','age':25,'address':'china'}person['gender']='male'gender=person['gender']print('gender=',gender)print('= '*20)'''删除字典中的元素'''person={'name':'谷哥的小弟','age':25,'address':'china'}del person['address']items=person.items();for item in items:    print(item)print('= '*20)'''利用clear()清空字典'''person={'name':'谷哥的小弟','age':25,'address':'china'}person.clear()count=len(person)print('清空后字典中元素个数=',count)print('= '*20)

结果如下：

name= 谷哥的小弟age= 25address= chinagender= 男= = = = = = = = = = = = = = = = = = = = 字典中的item= ('name', '谷哥的小弟')字典中的item= ('age', 25)字典中的item= ('address', 'china')字典中的key= name字典中的key= age字典中的key= address字典中的value= 谷哥的小弟字典中的value= 25字典中的value= chinaresult= False= = = = = = = = = = = = = = = = = = = = count= 3= = = = = = = = = = = = = = = = = = = = 修改后的age=27= = = = = = = = = = = = = = = = = = = = gender= male= = = = = = = = = = = = = = = = = = = = ('name', '谷哥的小弟')('age', 25)= = = = = = = = = = = = = = = = = = = = 清空后字典中元素个数= 0= = = = = = = = = = = = = = = = = = = =