Am just being curious but I would like to know whether python can be implemented in assembly and if not why has it not been done to help for speed issues. forgive my naivete in matters of programming languages.
The main implementation is written in C, and that's compiled to machine code (i.e. assembly made readable for the CPU). So writing it assembly is certainly possible, and if it's possible for a compiler, it's possible for humans - in theory. In practice, it is not even remotely practical. Not only asm is even more low-level than C (increasing development time significantly, perhaps even expotentially to the project size), it's also highly platform-specific, so each port takes a huge lot of work (and maintaince is multiplied by the number of supported platforms - quite a few in the case of CPython).
Apart from that, it's highly questionable if this would give a notable speed bonus. Writing it closer to the metal doesn't make stuff go faster magically (the contrary can be the case - you'd be hard-pressed to find a programmer who can consistently write better assembly than the four or five well-known C compilers). And much of Python's slowness comes from the many many abstractions and indirections the language consists of, not from a sloppy implementation of these.
A more promising approach (which is indeed followed by several alternative implementations) is a clever Just In Time-Compiler (JIT), which preserves all the dynamicness but exploits the fact that most Python programs make little use of that dynamicness by recognizing the most common paths at runtime and optimizing for these. Such complex programs are again not written in asm.
python implemented in assembly