lineno.py

#!/usr/bin/env python

import dis
import inspect

def lineno():
    """Returns the current line number in our program."""
    return inspect.currentframe().f_back.f_lineno

def test():
    print "hello, from line", lineno()

    print "hello, again from line", lineno()


def clone_code(c, firstlineno, lnotab):
    return (type(c)(c.co_argcount,c.co_nlocals,c.co_stacksize,c.co_flags,c.co_code,c.co_consts,c.co_names,c.co_varnames,c.co_filename,c.co_name,firstlineno,lnotab,c.co_freevars,c.co_cellvars))

def patch(f, line_mapping=dict()):
    tab = [i for i in f.func_code.co_lnotab]

    print "Line number table"
    print repr(''.join(tab))

    for op_pos, line_delta in zip((ord(tab[i]) for i in xrange(0, len(tab)-1, 2)), (ord(tab[i]) for i in xrange(1, len(tab), 2))):
        print op_pos, line_delta + f.func_code.co_firstlineno

    print "----"

    for i, line_delta in ((i, ord(tab[i])) for i in xrange(1, len(tab), 2)):
        print 'IDX', line_delta
        tab[i] = chr(line_delta + 1)

    print repr(''.join(tab))

    print "Before patching"
    dis.disassemble(f.func_code)

    f.func_code = clone_code(f.func_code, f.func_code.co_firstlineno, ''.join(tab))

    print "After patching"
    dis.disassemble(f.func_code)

if __name__ == '__main__':
    test()
    patch(test)
    test()

output

hello, from line 11
hello, again from line 13
Line number table
'\x00\x01\x0c\x02'
0 11
12 12
----
IDX 1
IDX 2
'\x00\x02\x0c\x03'
Before patching
 11           0 LOAD_CONST               1 ('hello, from line')
              3 PRINT_ITEM          
              4 LOAD_GLOBAL              0 (lineno)
              7 CALL_FUNCTION            0
             10 PRINT_ITEM          
             11 PRINT_NEWLINE       

 13          12 LOAD_CONST               2 ('hello, again from line')
             15 PRINT_ITEM          
             16 LOAD_GLOBAL              0 (lineno)
             19 CALL_FUNCTION            0
             22 PRINT_ITEM          
             23 PRINT_NEWLINE       
             24 LOAD_CONST               0 (None)
             27 RETURN_VALUE        
After patching
 12           0 LOAD_CONST               1 ('hello, from line')
              3 PRINT_ITEM          
              4 LOAD_GLOBAL              0 (lineno)
              7 CALL_FUNCTION            0
             10 PRINT_ITEM          
             11 PRINT_NEWLINE       

 15          12 LOAD_CONST               2 ('hello, again from line')
             15 PRINT_ITEM          
             16 LOAD_GLOBAL              0 (lineno)
             19 CALL_FUNCTION            0
             22 PRINT_ITEM          
             23 PRINT_NEWLINE       
             24 LOAD_CONST               0 (None)
             27 RETURN_VALUE        
hello, from line 12
hello, again from line 15

Shell codes for a new virus?

There is a trick to add new statements to python, but it breaks line positions in debugger and exception stack traces.
This was the first attempt to play with that. I have a complete solution at:

https://github.com/mmikulicic/python-match-statement