Notebook

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import panel as pn
from panel.widgets import ChatInterface

pn.extension()

The ChatInterface is a high-level widget, providing a user-friendly front-end interface for inputting different kinds of messages: text, images, PDFs, etc.

This widget provides front-end methods to:

Input (append) messages to the chat log.
Re-run (resend) the most recent user input ChatEntry.
Remove entries until the previous user input ChatEntry.
Clear the chat log, erasing all ChatEntry objects.

Since ChatInterface inherits from ChatFeed, it features all the capabilities of ChatFeed; please see ChatFeed.ipynb for its backend capabilities.

Chat Design Specification

Parameters:¶

Core¶

widgets (Widget | List[Widget]): Widgets to use for the input. If not provided, defaults to [TextInput].
user (str): Name of the ChatInterface user.
avatar (str | BinaryIO): The avatar to use for the user. Can be a single character text, an emoji, or anything supported by pn.pane.Image. If not set, uses the first character of the name.
reset_on_send (bool): Whether to reset the widget's value after sending a message; has no effect for TextInput.
auto_send_types (tuple): The widget types to automatically send when the user presses enter or clicks away from the widget. If not provided, defaults to [TextInput].

Styling¶

show_send (bool): Whether to show the send button. Default is True.
show_rerun (bool): Whether to show the rerun button. Default is True.
show_undo (bool): Whether to show the undo button. Default is True.
show_clear (bool): Whether to show the clear button. Default is True.
show_button_name (bool): Whether to show the button name. Default is True.

Properties:¶

active_widget (Widget): The currently active widget.
active (int): The currently active input widget tab index; -1 if there is only one widget available which is not in a tab.

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ChatInterface()

Although ChatInterface can be initialized without any arguments, it becomes much more useful, and interesting, with a callback.

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def even_or_odd(contents, user, instance):
    if len(contents) % 2 == 0:
        return "Even number of characters."
    return "Odd number of characters."

ChatInterface(callback=even_or_odd)

You may also provide a more relevant, default user name and avatar.

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ChatInterface(
    callback=even_or_odd,
    user="Asker",
    avatar="?",
    callback_user="Counter",
)

You can also use a different type of widget for input, like TextAreaInput instead of TextInput, by setting widgets.

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def count_chars(contents, user, instance):
    return f"Found {len(contents)} characters."

ChatInterface(
    callback=count_chars,
    widgets=pn.widgets.TextAreaInput(placeholder="Enter some text to get a count!"),
)

Multiple widgets can be set, which will be nested under a Tabs layout.

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def get_num(contents, user, instance):
    if isinstance(contents, str):
        num = len(contents)
    else:
        num = contents
    return f"Got {num}."

ChatInterface(
    callback=get_num,
    widgets=[
        pn.widgets.TextAreaInput(placeholder="Enter some text to get a count!"),
        pn.widgets.IntSlider(name="Number Input", end=10)
    ],
)

Widgets other than TextInput will require the user to manually click the Send button, unless the type is specified in auto_send_types.

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ChatInterface(
    callback=get_num,
    widgets=[
        pn.widgets.TextAreaInput(placeholder="Enter some text to get a count!"),
        pn.widgets.IntSlider(name="Number Input", end=10)
    ],
    auto_send_types=[pn.widgets.IntSlider],
)

If you include a FileInput in the list of widgets you can enable the user to upload files.

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ChatInterface(widgets=pn.widgets.FileInput(name="CSV File", accept=".csv"))

Try uploading a dataset! If you don't have a dataset in hand, download this sample dataset, penguins.csv.

Note, if you don't like the default renderer, pn.pane.DataFrame for CSVs, you can specify renderers to use pn.pane.Perspective; just be sure you have the extension added!

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pn.extension("perspective")

ChatInterface(
    widgets=pn.widgets.FileInput(name="CSV File", accept=".csv"),
    renderers=pn.pane.Perspective
)

If a list is provided to renderers, will attempt to use the first renderer that does not raise an exception.

In addition, you may render the input however you'd like with a custom renderer as long as the signature accepts one argument, namely value!

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def bad_renderer(value):
    raise Exception("Won't render using this...")

def custom_renderer(value):
    return pn.Column(
        f"Found {len(value)} rows in the CSV.",
        pn.pane.Perspective(value, height=600)
    )

ChatInterface(
    widgets=pn.widgets.FileInput(name="CSV File", accept=".csv"),
    renderers=[bad_renderer, custom_renderer]
)

If you'd like to guide the user into using one widget after another, you can set active in the callback.

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def guided_get_num(contents, user, instance):
    if isinstance(contents, str):
        num = len(contents)
        instance.active = 1  # change to IntSlider tab
    else:
        num = contents
        instance.active = 0  # Change to TextAreaInput tab
    return f"Got {num}."

pn.widgets.ChatInterface(
    callback=guided_get_num,
    widgets=[
        pn.widgets.TextAreaInput(placeholder="Enter some text to get a count!"),
        pn.widgets.IntSlider(name="Number Input", end=10)
    ],
)

Or, simply initialize with a single widget first, then replace with another widget in the callback.

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def get_num_guided(contents, user, instance):
    if isinstance(contents, str):
        num = len(contents)
        instance.widgets = [widgets[1]]  # change to IntSlider
    else:
        num = contents
        instance.widgets = [widgets[0]]  # Change to TextAreaInput
    return f"Got {num}."


widgets = [
    pn.widgets.TextAreaInput(placeholder="Enter some text to get a count!"),
    pn.widgets.IntSlider(name="Number Input", end=10)
]
pn.widgets.ChatInterface(
    callback=get_num_guided,
    widgets=widgets[0],
)

The currently active widget can be accessed with the active_widget property.

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widgets = [
    pn.widgets.TextAreaInput(placeholder="Enter some text to get a count!"),
    pn.widgets.IntSlider(name="Number Input", end=10)
]
chat_interface = pn.widgets.ChatInterface(
    widgets=widgets,
)
print(chat_interface.active_widget)

Sometimes, you may not want the widget to be reset after its contents has been sent.

To have the widgets' value persist, set reset_on_send=False.

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pn.widgets.ChatInterface(
    widgets=pn.widgets.TextAreaInput(),
    reset_on_send=False,
)

If you're not using an LLM to respond, the Rerun button may not be practical so it can be hidden by setting show_rerun=False.

The same can be done for other buttons as well with show_send, show_undo, and show_clear.

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pn.widgets.ChatInterface(callback=get_num, show_rerun=False, show_undo=False)

If you want a slimmer ChatInterface, use show_button_name=False to hide the labels of the buttons.

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pn.widgets.ChatInterface(callback=get_num, show_button_name=False, width=400)