我有数据透视表:
import 'package:flutter/material.dart';
import 'dart:convert';
List<MovementModel> movementModelFromJson(String str) =>
List<MovementModel>.from(
json.decode(str).map((x) => MovementModel.fromJson(x)));
String movementModelToJson(List<MovementModel> data) =>
json.encode(List<dynamic>.from(data.map((x) => x.toJson())));
class MovementDataSource extends ChangeNotifier {
List<Map> getAll() => _movement;
List<String> getMovements() => _movement
.map((map) => MovementModel.fromJson(map))
.map((item) => item.movement)
.toList();
// I'd like this to return a list of movement.variation.variationName
getVariationsByMovement(String movement) => _movement
.map((map) => MovementModel.fromJson(map))
.where((item) => item.movement == movement)
.map((item) => item.variation)
.expand((i) => i)
.toList();
List _movement = [
{
"movement": "Plank",
"alias": "plank",
"variation": [
{"variationName": "High Plank"},
{"variationName": "Forearm Plank"},
]
},
{
"movement": "Side Plank",
"alias": "side plank",
"variation": [
{"variationName": "Side Plank Right"},
{"variationName": "Side Plank Left"},
],
},
];
}
class MovementModel {
MovementModel({
this.movement,
this.alias,
this.variation,
});
String movement;
String alias;
List<VariationModel> variation;
factory MovementModel.fromJson(Map<String, dynamic> json) => MovementModel(
movement: json["movement"],
alias: json["alias"],
variation: List<VariationModel>.from(
json["variation"].map((x) => VariationModel.fromJson(x))),
);
Map<String, dynamic> toJson() => {
"movement": movement,
"alias": alias,
"variation": List<dynamic>.from(variation.map((x) => x.toJson())),
};
}
class VariationModel {
VariationModel({
this.variationName,
});
String variationName;
factory VariationModel.fromJson(Map<String, dynamic> json) => VariationModel(
variationName: json["variationName"],
);
Map<String, dynamic> toJson() => {
"variationName": variationName,
};
}
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
visualDensity: VisualDensity.adaptivePlatformDensity,
),
home: MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
int _counter = 0;
void _incrementCounter() {
List<VariationModel> vList =
MovementDataSource().getVariationsByMovement("Plank");
for (int i = 0; i < vList.length; i++) {
print(vList[i].variationName);
}
setState(() {
_counter++;
});
}
@override
Widget build(BuildContext context) {
List<VariationModel> vList =
MovementDataSource().getVariationsByMovement("Plank");
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: ListView.builder(
scrollDirection: Axis.vertical,
shrinkWrap: true,
itemCount: vList.length,
itemBuilder: (buildContext, index) {
return Card(
child: ListTile(
title: Text(
vList[index].variationName.toString(),
style: TextStyle(fontSize: 20),
),
trailing: Icon(Icons.keyboard_arrow_right),
onTap: () async {
Navigator.push(
context,
MaterialPageRoute(
builder: (_) =>
SelectDefaultItemPage(variation: vList[index])));
},
),
);
}),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: Icon(Icons.add),
),
);
}
}
class SelectDefaultItemPage extends StatelessWidget {
final VariationModel variation;
SelectDefaultItemPage({this.variation});
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text("test"),
),
body: Text(variation.variationName));
}
}
我正在尝试按总列的降序排序。我四处搜寻,发现了这段代码: ins_pivot.sort_values('Total',axis = 0,ascending = False),但似乎什么也没做。有帮助吗?
year 2016 2017 2018 2019 Total
type
A 2 1 1 0 4
B 1 0 0 0 1
C 91 418 512 437 1458