Tool to synchronize data to a slow device, e.g. a smartphone which is connected over MTP.
A state file (.mtp_sync_state.json) is created in the destination folder containing the time stamps of the synchronized files.
Python3.8 or newer.
ntlib.imp from here is used to set a basic log config. It is not necessary, just remove the import statement and ntimp.config_log if you do not want to download it.
Start the script with python mtp-sync.py [-h] or ./mtp-sync.py [-h] for more informations.
To find the path where your OS mounts mtp devices, search the internet.
I developed this script to send music to my smartphone. Since this is connected using MTP it does not support time stamps. Therefore rsync has some problems. I also tested other programs, but none of them satisfied me.
For the first synchronization (or if some data is already synchronized) you may want to call the script with options --size-only --write-state.