List<Data> datas = [];

Future<List<Data>> getData() async {
final response =
  await http.get('https://iptv-org.github.io/iptv/index.country.m3u');
final m3u = await M3uParser.parse(re,flutter,dart"/>
	














    

		

        

            
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首页  > 解决方案 > 如何保存列表 in flutter

List<Data> datas = [];

Future<List<Data>> getData() async {
final response =
  await http.get('https://iptv-org.github.io/iptv/index.country.m3u');
final m3u = await M3uParser.parse(re












flutter - 如何保存列表 in flutter

List<Data> datas = [];

Future<List<Data>> getData() async {
final response =
  await http.get('https://iptv-org.github.io/iptv/index.country.m3u');
final m3u = await M3uParser.parse(re





问题描述



List<Data> datas = [];

Future<List<Data>> getData() async {
final response =
  await http.get('https://iptv-org.github.io/iptv/index.country.m3u');
final m3u = await M3uParser.parse(response.body);

for (final entry in m3u) {
Data data = Data(entry.title, entry.attributes['tvg-logo'], entry.link,
    entry.attributes['tvg-language'], 'false');
datas.add(data);
}

return datas;
}


class Data {
String title;
String logo;
String url;
String language;
String isFavorite = 'false';

Data(this.title, this.logo, this.url, this.language, this.isFavorite);
}




Everytime I get the data from the url, then how I gonna save the list of Data object? Can I save the data using sharedPref?







How can i read a file from Azure Data Lake Gen 2 using python


I have a file lying in Azure Data lake gen 2 filesystem. I want to read the contents of the file and make some low level changes i.e. remove few characters from a few fields in the records. To be more explicit - there are some fields that also have the last character as backslash ('\'). And since the value is enclosed in the text qualifier (""), the field value escapes the '"' character and goes on to include the value next field too as the value of current field. 



for e.g. the text file contains the following 2 records (ignore the header)



-------------------------------------------------------------------
Name          | Address      | Description            | Remark
-------------------------------------------------------------------
"ABC"         | "UK"      | "descrption 1"            | "remark1"

"DEF"         | "USA"     | "description2\"           | "remark2"




When I read the above in pyspark data frame, it is read something like the following:



-------------------------------------------------------------------
Name          | Address      | Description            | Remark
-------------------------------------------------------------------
"ABC"         | "UK"      | "descrption 1"            | "remark1"

"DEF"         | "USA"     | "description2|remark2"    | null      




So, my objective is to read the above files using the usual file handling in python such as the follwoing and get rid of '\' character for those records that have that character and write the rows back into a new file.



f = open("test.txt",'r',encoding = 'utf-8')
//read the lines
//remove the '\' character 
//write the line back




But since the file is lying in the ADLS gen 2 file system (HDFS like file system), the usual python file handling wont work here. What is the way out for file handling of ADLS gen 2 file system?



Or is there a way to solve this problem using spark data frame APIs?


标签： flutterdart


解决方案









对于复杂的数据，建议使用数据库。您可以使用SqfLite包作为数据库。但你也可以使用共享首选项。使用quicktype.io创建模型，它将使用一些有用的方法创建模型，例如 toJson 和 fromJson。它还将生成 fromRawJson 和 toRawJson。这两种方法适用于字符串。您可以将模型转换为字符串并存储到 SharedPreferences 中，当您再次需要时将其转换为模型。










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