python學習(5)型別轉換 和例項
型別轉換:
字串轉為列表:
變數.split(" ")
(引號裡是符號,把字串通過什麼符號拆分,轉成列表(符號要是原來格式裡有的))
列表轉為字串:
" ".join(變數)
(引號裡是符號,把列表通過什麼符號轉成字串型別連線起來)
列表和元組互相轉換:
強制轉換
列表轉字典:
enumerate:獲取索引和值
前加dict強制轉換
字典轉列表:
變數.items() 迴圈
前加list強制轉換
例項:
例1:取出列表的最大值和最小值:
先排序,索引是0的最小,索引是1的最大
例2:取出複雜資料放入新列表:
{"code":0,"message":"Success","zpData":[{"name":"全國","code":100010000,"url":"/?city=100010000"},{"name":"北京","code":101010100,"url":"/beijing/"},{"name":"上海","code":101020100,"url":"/shanghai/"},{"name":"廣州","code":101280100,"url":"/guangzhou/"},{"name":"深圳","code":101280600,"url":"/shenzhen/"},{"name":"杭州","code":101210100,"url":"/hangzhou/"},{"name":"天津","code":101030100,"url":"/tianjin/"},{"name":"西安","code":101110100,"url":"/xian/"},{"name":"蘇州","code":101190400,"url":"/suzhou/"},{"name":"武漢","code":101200100,"url":"/wuhan/"},{"name":"廈門","code":101230200,"url":"/xiamen/"},{"name":"長沙","code":101250100,"url":"/changsha/"},{"name":"成都","code":101270100,"url":"/chengdu/"},{"name":"鄭州","code":101180100,"url":"/zhengzhou/"},{"name":"重慶","code":101040100,"url":"/chongqing/"},{"name":"佛山","code":101280800,"url":"/foshan/"},{"name":"合肥","code":101220100,"url":"/hefei/"},{"name":"濟南","code":101120100,"url":"/jinan/"},{"name":"青島","code":101120200,"url":"/qingdao/"},{"name":"南京","code":101190100,"url":"/nanjing/"},{"name":"東莞","code":101281600,"url":"/dongguan/"},{"name":"昆明","code":101290100,"url":"/kunming/"},{"name":"南昌","code":101240100,"url":"/nanchang/"},{"name":"石家莊","code":101090100,"url":"/shijiazhuang/"},{"name":"寧波","code":101210400,"url":"/ningbo/"},{"name":"福州","code":101230100,"url":"/fuzhou/"}]}
檢視複雜資料結構工具:
https://www.bejson.com/jsonviewernew/
需求1:取出以下資料中的城市:
可以看到是一個字典序列,城市在”zpData“鍵對應的值中。
先for ...in....取出zpData對應的值,定義為item(這是一個字典)
再把item字典中的name鍵對應的值取出來(也就是這些城市),append新增到list1中。
需求2:取出除了“全國”外的所有拼音,並且不要/斜槓:
①先for ...in....取出zpData對應的值,定義為a(這是一個字典),檢視a是這樣的:
②再從中取出”url“鍵對應的值,是這樣的:
③用if條件去掉全國的,是這樣的:
④去掉/斜槓:(用replace)
⑤把上面print()中的這些,append增加到list1 這個列表中: