python-package/lets_plot/frontend_context/_json_contexts.py

#  Copyright (c) 2020. JetBrains s.r.o.
#  Use of this source code is governed by the MIT license that can be found in the LICENSE file.

import os

from ._frontend_ctx import FrontendContext
from ._intellij_python_json_ctx import IntellijPythonJsonContext


def _create_json_frontend_context() -> FrontendContext:
    """
    Configures Lets-Plot JSON output.

    Such context requires a Lets-Plot JSON interpreter plugged in to the frontend env (like PyCharm)
    """

    if _is_Intellij_Python_Lets_Plot_Plugin():
        return IntellijPythonJsonContext()

    # ToDo: GenericJsonFrontendContext
    raise RuntimeError("Couldn't detect Intellij Python environment")


def _is_Intellij_Python_Lets_Plot_Plugin() -> bool:
    try:
        # An empty marker module defined by Intellij Lets-Plot plugin
        # import lets_plot_intellij_python_plugin  <---- the old way.


        # The check above is not working with PyCharm remote interpreter: https://github.com/JetBrains/lets-plot/issues/348

        # 1) The "datalore.display" is present in both PyCharm and Datalore env.
        #    See `intellij.python.helpers` module in IDEA.
        from datalore.display import display

        # 2) The "DATALORE_HOME" is only present in Datalore env but not in PyCharm env.
        return "DATALORE_HOME" not in os.environ
    except ImportError:
        return False