Custom matplotlib and plotly.py's fig.show()

matplotlib_custom.py

"""matplotlib.use('module://matplotlib_custom'), remember to add this file to PYTHONPATH"""

from matplotlib.backend_bases import Gcf
from matplotlib.backends.backend_agg import FigureCanvasAgg

FigureCanvas = FigureCanvasAgg

def show(*args, **kwargs):
    var = globals().get('custom')
    if var:
        context = var.get('context')
        for figmanager in Gcf.get_all_fig_managers():
            buffer = BytesIO()
            figmanager.canvas.figure.savefig(buffer, format='png')
            buffer.seek(0)
            png = buffer.getvalue()
            buffer.close()
            url = f'data:image/png;base64,{b64encode(png).decode('utf-8')}'
            payload = { "type": "image", "data": url }
            context.preview(payload)
    else:
        print('matplotlib_custom: no globals().get("custom")', file=sys.stderr)

plotly_custom.py

from plotly.io import renderers
from plotly.io.base_renderers import ExternalRenderer

class CustomRenderer(ExternalRenderer):
    def render(self, fig_dict):
        from plotly.io import to_html
        html = to_html(
            fig_dict,
            include_plotlyjs=True,
            include_mathjax="cdn",
            full_html=True,
            default_width="100%",
            default_height="100%",
            validate=False,
        )
        globals().get('custom').get('context').html(html)

renderers['custom'] = CustomRenderer()
renderers.default = 'custom'