Flutter Python集成插件python_ffi_dart的使用

Flutter Python集成插件python_ffi_dart的使用

python_ffi_dart 是一个用于 Dart 的 Python 外部函数接口（FFI）。它允许您轻松地将任何纯 Python 模块导入到您的 Dart 或 Flutter 项目中。

使用入门

注意：此包旨在用于 Dart 控制台项目，对于 Flutter 应用程序，请参见 python_ffi 包。详细的使用说明可以在文档中找到。

示例项目

查看示例项目以获得一个工作的示例。

限制条件

在 Linux 和 Windows 上，此包期望系统上安装了 python3.11 并且可以在 PATH 中找到。Python 动态库不包含在包中，您必须通过指定 libPath 来使用本地副本调用 PythonFfiDart.instance.initialize()。

完整示例 Demo

以下是一个完整的示例，展示如何在 Flutter 项目中使用 python_ffi_dart 插件与 Python 进行交互：

import "dart:typed_data";
import "package:collection/collection.dart";
import "package:python_ffi_dart/python_ffi_dart.dart";

// 定义类型映射条目类
typedef SendTyPythonCallback<T> = void Function({required T value});
typedef ReceiveFromPythonCallback<T> = T Function();

class TypeMappingEntry<T extends Object?> {
  const TypeMappingEntry({
    required this.pythonType,
    required this.value,
    this.dartType,
    this.sendToPython,
    this.receiveFromPython,
    this.equals,
  });

  final String? dartType;
  final String pythonType;
  final T value;
  final SendTyPythonCallback<T>? sendToPython;
  final ReceiveFromPythonCallback<T>? receiveFromPython;
  final bool Function(T, T)? equals;

  String get _dartType => dartType ?? T.toString();

  bool Function(T, T) get _equals => equals ?? (T a, T b) => a == b;

  void run() {
    try {
      print("\ntesting $_dartType ←→ $pythonType");
      final SendTyPythonCallback<T>? sendToPython = this.sendToPython;
      if (sendToPython == null) {
        print("├── dart -> python skipped ⚠️");
      } else {
        sendToPython(value: value);
        print("├── dart -> python successful ✅");
      }

      final ReceiveFromPythonCallback<T>? receiveFromPython =
          this.receiveFromPython;
      if (receiveFromPython == null) {
        print("└── python -> dart skipped ⚠️");
      } else {
        final T receivedValue = receiveFromPython();
        assert(
          _equals(receivedValue, value),
          "Python returned $receivedValue, but expected $value",
        );
        print("└── python -> dart successful ✅");
      }
    } on Exception catch (e) {
      print("└── ❌ error: $e");
    }
  }
}

Future<void> typeMappings() async {
  // 导入 Python 模块
  final type_mappings module = type_mappings.import();

  // 测试不同的数据类型映射
  TypeMappingEntry<Null>(
    dartType: "null",
    pythonType: "None",
    value: null,
    sendToPython: module.receive_none,
    receiveFromPython: module.request_none,
  ).run();

  TypeMappingEntry<bool>(
    dartType: "true",
    pythonType: "True",
    value: true,
    sendToPython: module.receive_bool_true,
    receiveFromPython: module.request_bool_true,
  ).run();

  TypeMappingEntry<bool>(
    dartType: "false",
    pythonType: "False",
    value: false,
    sendToPython: module.receive_bool_false,
    receiveFromPython: module.request_bool_false,
  ).run();

  TypeMappingEntry<int>(
    pythonType: "int",
    value: 42,
    sendToPython: module.receive_int,
    receiveFromPython: module.request_int,
  ).run();

  TypeMappingEntry<double>(
    pythonType: "float",
    value: 3.14,
    sendToPython: module.receive_float,
    receiveFromPython: module.request_float,
  ).run();

  TypeMappingEntry<String>(
    pythonType: "str",
    value: "Hello World",
    sendToPython: module.receive_str,
    receiveFromPython: module.request_str,
  ).run();

  TypeMappingEntry<Uint8List>(
    pythonType: "bytes",
    value: Uint8List.fromList("Hello World".codeUnits),
    sendToPython: module.receive_bytes,
    receiveFromPython: module.request_bytes,
  ).run();

  TypeMappingEntry<Map<String, int>>(
    pythonType: "dict[str, int]",
    value: const <String, int>{"one": 1, "two": 2, "three": 3},
    sendToPython: module.receive_dict,
    receiveFromPython: module.request_dict,
    equals: const MapEquality<String, int>().equals,
  ).run();

  TypeMappingEntry<List<int>>(
    pythonType: "list[int]",
    value: const <int>[1, 2, 3],
    sendToPython: module.receive_list,
    receiveFromPython: module.request_list,
    equals: (List<int> a, List<int> b) =>
        const ListEquality<int>().equals(a, b),
  ).run();

  // 其他类型的测试可以类似地进行
}

void _expectEqTest(Object? a, Object? b, {required bool expected}) {
  try {
    print("\ntesting $a == $b, expecting $expected");
    final bool result = a == b;
    if (result == expected) {
      print("└── successful ✅");
    } else {
      print("└── ❌ failed");
    }
  } on Exception catch (e) {
    print("└── ❌ error: $e");
  }
}

Future<void> eqTest() async {
  // 类型相等性测试逻辑
}