将 ipywidgets.widgets.widget_output.Output 转换为列表

Question

我创建了一个功能，允许用户从清单中进行选择并 return 选定的值。问题是 returned 清单的类型是 ipywidgets.widgets.widget_output.Output，我找不到提取结果中的值的方法。

import ipywidgets as widgets

def create_checklist():
    data = {"label1": "data1", "label2": "data2"}

    names = []
    checkbox_objects = []
    for key in data:
        checkbox_objects.append(widgets.Checkbox(value=False, description=key))
        names.append(key)

    arg_dict = {names[i]: checkbox for i, checkbox in enumerate(checkbox_objects)}

    ui = widgets.VBox(children=checkbox_objects)

    selected_data = []
    def select_data(**kwargs):
        selected_data.clear()

        for key in kwargs:
            if kwargs[key] is True:
                selected_data.append(key)

        print(selected_data)

    out = widgets.interactive_output(select_data, arg_dict)
    display(ui)
    return out

checklist = create_checklist()

print("Displays just fine: ")
display(checklist)

print("But cannot print or use in any way. Print result: ")
print(checklist)

print(f"\nChecklist type: {type(checklist)}")

选择'label2'后结果：

Displays just fine: 
['label2']

But cannot print or use in any way. Print result: 
Output()

Checklist type: <class 'ipywidgets.widgets.widget_output.Output'>

在某些情况下，您还可以将其打印（清单）并得出：

Output(outputs=({'output_type': 'stream', 'text': "['label2']\n", 'name': 'stdout'},))

我显然已经尝试过 list(checklist)、checklist.text、checklist['text']，但无济于事。

Answer 1

尝试将您的 selected_data 列表移至全局范围：


import ipywidgets as widgets

selected_data = []   # in global scope rather than local scope to function

def create_checklist():
    data = {"label1": "data1", "label2": "data2"}

    names = []
    checkbox_objects = []
    for key in data:
        checkbox_objects.append(widgets.Checkbox(value=False, description=key))
        names.append(key)

    arg_dict = {names[i]: checkbox for i, checkbox in enumerate(checkbox_objects)}

    ui = widgets.VBox(children=checkbox_objects)


    def select_data(**kwargs):
        selected_data.clear()

        for key in kwargs:
            if kwargs[key] is True:
                selected_data.append(key)

        print(selected_data)

    out = widgets.interactive_output(select_data, arg_dict)
    display(ui)
    return out

checklist = create_checklist()

那么您应该可以在后续单元格中的任意位置调用 selected_data 并获取当前选定的值。

Answer 2

实际上，经过进一步调查，问题不在于局部变量 v 全局变量，它只是 return 正确的局部变量！只需 return 'selected_data' 而不是 out，它 return 就是一个选择列表！

import ipywidgets as widgets

def create_checklist():
    data = {"label1": "data1", "label2": "data2"}

    names = []
    checkbox_objects = []
    for key in data:
        checkbox_objects.append(widgets.Checkbox(value=False, description=key))
        names.append(key)

    arg_dict = {names[i]: checkbox for i, checkbox in enumerate(checkbox_objects)}

    ui = widgets.VBox(children=checkbox_objects)

    selected_data = []
    def select_data(**kwargs):
        selected_data.clear()

        for key in kwargs:
            if kwargs[key] is True:
                selected_data.append(key)

        print(selected_data)

    out = widgets.interactive_output(select_data, arg_dict)
    display(ui)
    return selected_data

checklist = create_checklist()

print("Print checklist: ")
display(checklist)

print(f"\nChecklist type is list: {type(checklist)}")

将 ipywidgets.widgets.widget_output.Output 转换为列表

Converting ipywidgets.widgets.widget_output.Output to a list

python

python-3.x

ipywidgets