-
二维数组:
有多个数组
info = [ ['name','1111','beijing'], ['name1', '2222', 'shanghai'] ]
多维数组的取值:
info = [ ['name','1111','beijing'], ['name1', '2222', 'shanghai'] ] print(info[1][-1])
2.字典
- :用{}表示,字典中不能有重复的key
infos = {}
infos = { 'xiaohong','19' 'xiaohei','20' } print(infos)
增加:
infos = {
'xiaohong':'19',
'xiaohei':'20'
}
infos ['xiaolv']=45 infos.setdefault('xiaoming',4) print (infos)
增加:
infos ['xiaolv']=45 ,用这种方法, key有重复值,values会替换
infos.setdefault('xiaoming',4),
setdefault这用种方法,key一样, values不会替换
修改
infos [ 需要修改的值] = ‘需要更新的值’
infos = { 'xiaohong':'19', 'xiaohei':'20' } infos ['xiaohong'] = 43 print (infos)
删除:pop
如果删除一个不存在值,会报错
infos = { 'xiaohong':'19', 'xiaohei':'20' } infos .pop('xiaohong') print (infos)
删除:del
infos = { 'xiaohong':'19', 'xiaohei':'20' } del infos ['xiaohong'] print (infos)
取值:get方法
infos = { 'xiaohong':'19', 'xiaohei':'20' } print(infos.get('xiaohong'))
取一个不存在的values,返回none
如果默认取不到一个值,可以在get后面加一个
eg:
infos = { 'xiaohong':'19', 'xiaohei':'20' } print(infos['xiaohei'])
不存在的values,会报错
清空一个字典
infos = { 'xiaohong':'19', 'xiaohei':'20' } infos.clear() print(infos)
返回一个key
infos = { 'xiaohong':'19', 'xiaohei':'20' } print(infos.keys())
返回所有的values
infos = { 'xiaohong':'19', 'xiaohei':'20' } print(infos.values())
字典转换成二维数组
infos = { 'xiaohong':'19', 'xiaohei':'20' } print(infos.items())
更新一个值:
infos = { 'xiaohong':'19', 'xiaohei':'20' } infos.update(xiaohong='女') print(infos)
或者增加一个值
infos = { 'xiaohong':'19', 'xiaohei':'20' } infos.update(xiaohong='女',money=33999) print(infos)