I bought a raspberry pi and created a small remote controlled truck, but I want to work on more projects; is there any way to sore the Python file onto a flashdrive and connect it to some kind of cpu so the truck will still work and I can use the pi for other things and continue buying the small "cpu" uploading the pythons code and moving forward on different projects?
You've written in a high-level language for specific hardware. 
You could make your own ARM Cortex-A7 based board but it'll be cheaper to just buy another Pi.
If you want to make small inexpensive devices, then you should use a lower-level language with a microcontroller, such as Atmel AVR, found in Arduinos.
How do I take code from a raspberry pi and store it onto a smaller chip so I don't have to use the pi over and over again