Python importlib 模块，abc() 实例源码

def test_load_module_API(self):
        # If fullname is not specified that assume self.name is desired.
        class TesterMixin(importlib.abc.Loader):
            def load_module(self, fullname): return fullname
            def module_repr(self, module): return '<module>'

        class Tester(importlib.abc.FileLoader, TesterMixin):
            def get_code(self, _): pass
            def get_source(self, _): pass
            def is_package(self, _): pass

        name = 'mod_name'
        loader = Tester(name, 'some_path')
        self.assertEqual(name, loader.load_module())
        self.assertEqual(name, loader.load_module(None))
        self.assertEqual(name, loader.load_module(name))
        with self.assertRaises(ImportError):
            loader.load_module(loader.name + 'XXX')

def test_get_filename_API(self):
        # If fullname is not set then assume self.path is desired.
        class Tester(importlib.abc.FileLoader):
            def get_code(self, _): pass
            def get_source(self, _): pass
            def is_package(self, _): pass
            def module_repr(self, _): pass

        path = 'some_path'
        name = 'some_name'
        loader = Tester(name, path)
        self.assertEqual(path, loader.get_filename(name))
        self.assertEqual(path, loader.get_filename())
        self.assertEqual(path, loader.get_filename(None))
        with self.assertRaises(ImportError):
            loader.get_filename(name + 'XXX')

    # [basic]

def open_module(self, event=None):
        # XXX Shouldn't this be in IOBinding?
        try:
            name = self.text.get("sel.first", "sel.last")
        except TclError:
            name = ""
        else:
            name = name.strip()
        name = tkSimpleDialog.askstring("Module",
                 "Enter the name of a Python module\n"
                 "to search on sys.path and open:",
                 parent=self.text, initialvalue=name)
        if name:
            name = name.strip()
        if not name:
            return
        # XXX Ought to insert current file's directory in front of path
        try:
            spec = importlib.util.find_spec(name)
        except (ValueError, ImportError) as msg:
            tkMessageBox.showerror("Import error", str(msg), parent=self.text)
            return
        if spec is None:
            tkMessageBox.showerror("Import error", "module not found",
                                   parent=self.text)
            return
        if not isinstance(spec.loader, importlib.abc.SourceLoader):
            tkMessageBox.showerror("Import error", "not a source-based module",
                                   parent=self.text)
            return
        try:
            file_path = spec.loader.get_filename(name)
        except AttributeError:
            tkMessageBox.showerror("Import error",
                                   "loader does not support get_filename",
                                   parent=self.text)
            return
        if self.flist:
            self.flist.open(file_path)
        else:
            self.io.loadfile(file_path)

def open_module(self, event=None):
        # XXX Shouldn't this be in IOBinding?
        try:
            name = self.text.get("sel.first", "sel.last")
        except TclError:
            name = ""
        else:
            name = name.strip()
        name = tkSimpleDialog.askstring("Module",
                 "Enter the name of a Python module\n"
                 "to search on sys.path and open:",
                 parent=self.text, initialvalue=name)
        if name:
            name = name.strip()
        if not name:
            return
        # XXX Ought to insert current file's directory in front of path
        try:
            spec = importlib.util.find_spec(name)
        except (ValueError, ImportError) as msg:
            tkMessageBox.showerror("Import error", str(msg), parent=self.text)
            return
        if spec is None:
            tkMessageBox.showerror("Import error", "module not found",
                                   parent=self.text)
            return
        if not isinstance(spec.loader, importlib.abc.SourceLoader):
            tkMessageBox.showerror("Import error", "not a source-based module",
                                   parent=self.text)
            return
        try:
            file_path = spec.loader.get_filename(name)
        except AttributeError:
            tkMessageBox.showerror("Import error",
                                   "loader does not support get_filename",
                                   parent=self.text)
            return
        if self.flist:
            self.flist.open(file_path)
        else:
            self.io.loadfile(file_path)
        return file_path