table_of_contents.py

import streamlit as st

class Toc:
    # TOC class made by https://discuss.streamlit.io/u/synode
    # Taken from https://discuss.streamlit.io/t/table-of-contents-widget/3470/7
    def __init__(self):
        self._items = []
        self._placeholder = None

    def title(self, text):
        self._markdown(text, "h1")

    def header(self, text):
        self._markdown(text, "h2", " " * 2)

    def subheader(self, text):
        self._markdown(text, "h3", " " * 4)

    def placeholder(self, sidebar=False):
        self._placeholder = st.sidebar.empty() if sidebar else st.empty()

    def generate(self):
        if self._placeholder:
            self._placeholder.markdown("\n".join(self._items), unsafe_allow_html=True)

    def _markdown(self, text, level, space=""):
        key = "".join(text.replace(' - ','-').replace(' & ','-').replace('.','-').replace(' ','-')).lower()

        st.markdown(f"<{level} id='{key}'>{text}</{level}>", unsafe_allow_html=True)
        self._items.append(f"{space}* <a href='#{key}'>{text}</a>")