Example of how WSGI python server

funicorn.py

# Sibling Fake of gunicorn
import os
import sys
from typing import List, Tuple


class Funicorn:

    def __init__(self, app_path: str):
        self.application = load_application(application_path)
        self.buffer_output = sys.stdout.buffer
        self.set_environ()

    def set_environ(self):
        self.environ = {**os.environ}

        self.environ['wsgi.input'] = sys.stdin.buffer
        self.environ['wsgi.errors'] = sys.stderr.buffer

    def write(self, data: bytes):
        self.buffer_output.write(data)

    def write_headers(self, status, headers: List[Tuple(str, str)]):
        self.write(f'Status: {status}\r\n'.encode())

        for hkey, hvalue in headers:
            self.write(f'{hkey}: {hvalue}\r\n'.encode())

            self.write('\r\n'.encode())

    def start_response(self, status, response_headers: List[Tuple(str, str)], **kwargs):
        self.write_headers(status, response_headers)

    def finish(self):
        self.buffer_output.flush()

    def run(self):
        response_body = self.application({**self.environ}, self.start_response)
        self.write(response_body)


if __name__ == 'main':
    application_path = 'path_to_fango.app'
    funicorn = Funicorn(application_path)

    funicorn.run()