A volatile variable is a variable that is marked or cast with the keyword "volatile" so that the variable can be changed by some outside factor, such as the operating system or other software.
There is no volatile concept in Python. Python stores all objects on a heap, in main memory. Moreover, due to how the Python interpreter loop uses locking (the GIL), only one thread at a time will be actively running Python code. There is never a chance that different threads are running a Python interpreter loop on a different CPU.
Javascript also has no volatile because JavaScript run-times are single threaded. This means that there is is nothing to interrupt this code and no other code can change the state while the code runs.