How to visualize the geometry by cutting into part

I tried visualizing the uploaded .stl file into webpage with the below code.

Now if I want to visualize the geometry by cutting into 2 parts to see the inner view, how this can be achieved.?

import streamlit as st
import pyvista as pv
from stpyvista import stpyvista
import mimetypes

# ipythreejs does not support scalar bars :(
pv.global_theme.show_scalar_bar = False 
plotter = pv.Plotter(
plotter.background_color = "white"

color = st.sidebar.selectbox("Pick a color:",["green","white","yellow","blue","red"])

## Initialize pyvista reader and plotter
reader = pv.STLReader("D://4_im//cub.stl")

# Read data and send to plotter
mesh =

# Final touches
plotter.background_color = "white"

# Pass a key to avoid re-rendering at each time something changes in the page