Sending an obj or stl file to 3D printer via USB

I have just configured my computer to send .obj or .stl files via Makerbot Desktop to 3D printing. Now, I want to send them to 3D printing to the printer programatically. I thought about two options: (1) Send using developer API of makerbot. (2) send via usb port using one of the popular languages such as python. For (1) I tried to get an access for API but didn't receive any response after registration. For (2) It seems there is no module for Python that allows you to send files to 3D printer.
Is there a way to send files to 3D printer programatically (without using Makerbot Desktop)?