The last Micro Web Server for IoTs (MicroPython) or large servers (CPython), that supports WebSockets, routes, template engine and with really optimized architecture (mem allocations, async I/Os). Ready for ESP32, STM32 on Pyboard, Pycom's chipsets (WiPy, LoPy, ...). Robust, efficient and documented!
No, you must handle request and process the data posted yourself.
But a good way is to send file using javascript binary buffer through a websocket for example :)
Is it possible to receive a file upload via HttpRequest?