how operators are implemented as function calls

[Gribouillis]

i've noted that a few posts show that some of you know about expressing an assembly-like language that expresses what goes on inside Python (or at least inside CPython).

Do you mean bytecode? Try the dis module

>>> import dis
>>> dis.dis("mydict[x] = y")
  1           0 LOAD_NAME                0 (y)
              3 LOAD_NAME                1 (mydict)
              6 LOAD_NAME                2 (x)
              9 STORE_SUBSCR
             10 LOAD_CONST               0 (None)
             13 RETURN_VALUE
>>> dis.dis("y = mydict[x]")
  1           0 LOAD_NAME                0 (mydict)
              3 LOAD_NAME                1 (x)
              6 BINARY_SUBSCR
              7 STORE_NAME               2 (y)
             10 LOAD_CONST               0 (None)
             13 RETURN_VALUE