#!/usr/bin/env python
# # # # # # # # # # # # #
# Create a code object  #
# # # # # # # # # # # # #
"""
>>> from types import CodeType
>>> help(CodeType)
Help on class code in module builtins:

class code(object)
 |  code(argcount, kwonlyargcount, nlocals, stacksize, flags, codestring,
 |        constants, names, varnames, filename, name, firstlineno,
 |        lnotab[, freevars[, cellvars]])
 |  
 |  Create a code object.  Not for the faint of heart.
...

"""
from types import CodeType
from dis import dis
import sys

if sys.version_info.major < 3:
    print("You need python 3 to run this code.")
    sys.exit(1)

co_code = bytes([101, 0, 0,    #Load print function
                 101, 1, 0,    #Load name 'a'
                 101, 2, 0,    #Load name 'b'
                 23,           #Take first two stack elements and store their sum
                 131, 1, 0,    #Call first element in the stack with one positional argument
                 1,            #Pop top of stack
                 101, 0, 0,    #Load print function
                 101, 1, 0,    #Load name 'a'
                 101, 2, 0,    #Load name 'b'
                 20,           #Take first two stack elements and store their product
                 131, 1, 0,    #Call first element in the stack with one positional argument
                 1,            #Pop top of stack
                 100, 0, 0,    #Load constant None
                 83])          #Return top of stack

lnotab = bytes([14,1])

my_code = CodeType(
            0,
            0,
            0,
            3,
            64,
            co_code,
            (None,),
            ('print', 'a', 'b'),
            (),
            'my_code_filename',
            'my_code',
            1,
            lnotab,
            freevars=(),
            cellvars=() )


def main():
    a=2
    b=7

    print('Print the sum and the product of a=%s and b=%s:' % (a, b))
    exec(my_code) # code prints the sum and the product of "a" and "b"

    print('\nDisassemble the code:')
    dis(my_code) # disassemble the code


if __name__ == '__main__':
    main()