Detecting if ipython notebook is outputting to a terminal

Question

I want to detect if a Jupyter Notebook is being executed in a terminal e.g. via ipython --TerminalIPythonApp.file_to_run command, as opposite to a HTML enabled notebook. Note that this is different from detecting if the Python code is run with python or within a notebook.

Based on this I can format Pandas DataFrames suitable either for HTML or for terminal display.

How can I detect if a notebook is outputting to a terminal?

Answer 1

Based on William's answer I figured this out.

Terminal output example:

HTML output example:

Here is some sample code, cleaned up from William's answer and also some more context how this can be utilised.

See an example quantitative finance notebook using this. See full source code.

"""Helpers to deal with Jupyter Notebook issues."""
import enum
from typing import Callable

import pandas as pd
from IPython import get_ipython
from IPython.display import display
from IPython.terminal.interactiveshell import TerminalInteractiveShell
from ipykernel.zmqshell import ZMQInteractiveShell


class JupyterOutputMode(enum.Enum):
    """What kind of output Jupyter Notebook supports."""

    #: We could not figure out - please debug
    unknown = "unknown"

    #: The notebook is run by terminal
    terminal = "terminal"

    #: Your normal HTML notebook
    html = "html"


def get_notebook_execution_mode() -> JupyterOutputMode:
    """Determine if the Jupyter Notebook supports HTML output."""

    # See https://stackoverflow.com/questions/70768390/detecting-if-ipython-notebook-is-outputting-to-a-terminal
    # for discussion
    ipython = get_ipython()

    if isinstance(ipython, TerminalInteractiveShell):
        # Hello ANSI graphics my old friend
        return JupyterOutputMode.terminal
    elif isinstance(ipython, ZMQInteractiveShell):
        # MAke an assumption ZMQ instance is a HTML notebook
        return JupyterOutputMode.html

    return JupyterOutputMode.unknown


def display_with_styles(df: pd.DataFrame, apply_styles_func: Callable):
    """Display a Pandas dataframe as a table.

    DataFrame styler objects only support HTML output.
    If the Jupyter Notebook output does not have HTML support,
    (it is a command line), then display DataFrame as is
    without styles.

    For `apply_style_func` example see :py:method:`tradingstrategy.analysis.portfolioanalyzer.expand_timeline`.

    :param df: Pandas Dataframe we want to display as a table.

    :param apply_styles_func: A function to call on DataFrame to add its styles on it.
        We need to pass this as callable due to Pandas architectural limitations.
        The function will create styles using `pandas.DataFrame.style` object.
        However if styles are applied the resulting object can no longer be displayed in a terminal.
        Thus, we need to separate the procses of creating dataframe and creating styles and applying them.

    """
    mode = get_notebook_execution_mode()
    if mode == JupyterOutputMode.html:
        display(apply_styles_func(df))
    else:
        display(df)