app.py

#!/usr/bin/env python
import os
from flask import Flask, send_file

"""
flask run
DIR=files/good_output/good/ flask run
"""

app = Flask(__name__)
#root = os.path.join(os.path.dirname(os.path.abspath(__file__)), '_site')
root = os.path.join(os.getcwd(), '_site')
root = os.environ.get('DIR', root)

@app.route("/")
def main():
    return send_file(os.path.join(root, 'index.html'))

@app.route("/<path:fullpath>")
def all(fullpath):
    extensions = ['.js', '.css', '.json', '.ico']
    for ext in extensions:
        if fullpath.endswith(ext):
            path = os.path.join(root, fullpath)
            if os.path.exists(path):
                return send_file(path)
            else:
                #print(f"No file {path}")
                return '', 404
    if fullpath.endswith('/'):
        fullpath += 'index'
    return send_file(os.path.join(root, f"{fullpath}.html"))

if __name__ == "__main__":
    app.run(debug=True)