generate a pyc file by hand. the bytecode's content is something like test.py content.

make_bytecode.py

import marshal
import struct
import time
import imp
from opcode import opmap

def f(): return
code = type(f.__code__)     # the code object type

code_list = (
        struct.pack('B', opmap['LOAD_CONST']),
        struct.pack('H', 0),
        struct.pack('B', opmap['STORE_NAME']),
        struct.pack('H', 0),
        struct.pack('B', opmap['LOAD_CONST']),
        struct.pack('H', 1),
        struct.pack('B', opmap['STORE_NAME']),
        struct.pack('H', 1),
        struct.pack('B', opmap['LOAD_NAME']),
        struct.pack('H', 0),
        struct.pack('B', opmap['LOAD_NAME']),
        struct.pack('H', 1),
        struct.pack('B', opmap['BINARY_ADD']),
        struct.pack('B', opmap['PRINT_ITEM']),
        struct.pack('B', opmap['PRINT_NEWLINE']),
        struct.pack('B', opmap['LOAD_CONST']),
        struct.pack('H', 2),
        struct.pack('B', opmap['RETURN_VALUE']),
    )

code_string = ''.join(code_list)

code_args = (
        0,                          # 'argcount' arguments count of the code object
        0,                          # 'nlocals' ??
        2,                          # 'stack_size' max size of the stack
        64,                         # 'flags' ??
        code_string,                # 'codestring' the bytecode instructions
        (1, 2, None),               # 'constants' constants value for the code object
        ('a', 'b'),                 # 'names' used names in this code object
        (),                         # 'varnames' variable names
        'test.py',                  # 'filename' filename
        '<module>',                 # 'name' name of the function/class/module
        1,                          # 'firstlineno' the first line number of this code object
        '\x06\x01\x06\x01',         # 'lnotab' ??
        (),                         # 'freevars' for closure
        (),                         # 'cellvars': ??
    )

co = code(*code_args)

bytecode_head = '\x03\xf3\r\n\x0f\x1c\x8aP'             # magic number for 2.7

magic_string = imp.get_magic()
time_string = struct.pack('L', int(time.time()))

if __name__ == '__main__':
    f = open('test.pyc', 'wb')
    f.write(magic_string)
    f.write(time_string)
    marshal.dump(co, f)
    print 'done!'

test.py

a = 1
b = 2
print a + b