speeding up infinite loops in python

fuckery.py

"""
have you ever wanted to make your infinite loops terminate a little
quicker? well, now you can!

python -i fuckery.py
>>> mangle()
>>> while True:
...     pass
>>> # finishes instantly!

linux only, cpython 3.9+

note that it only works on code that is parsed after mangle() is
called, i.e. code in the same file as mangle() will not be affected.
"""

import ctypes

def find_data(prot):
    maps = open("/proc/self/maps").read()
    modname = 'libpython3' if 'libpython3' in maps else '/bin/python3'
    for x in maps.splitlines():
        row = x.split()
        if row[1] == prot and modname in row[-1]:
            yield range(*[int(x, 16) for x in row[0].split('-')])

def mangle():
    ptr_sz = ctypes.sizeof(ctypes.c_void_p)
    data = next(find_data('rw-p'))
    rodata = list(find_data('r--p'))
    trues, falses = [], []
    for x in data[::ptr_sz]:
        ptr = ctypes.c_void_p.from_address(x).value
        if ptr and any(ptr in r for r in rodata):
            if ctypes.string_at(ptr, 5) == b'True\0': trues += [x]
            elif ctypes.string_at(ptr, 6) == b'False\0': falses += [x]
    [true], [false] = trues, falses
    int32_at = ctypes.c_int32.from_address
    int32_at(true + ptr_sz).value = int32_at(false + ptr_sz).value