zip-xform

#!/usr/bin/env python3
from copy import copy
from shutil import copyfileobj
from sys import argv, stderr
from zipfile import ZipFile

zi = ZipFile(argv[1], "r")
zo = ZipFile(argv[2], "w")
xform = argv[3]

for zim in zi.infolist():
    exec(xform, (ctx := {"m": copy(zim)}))

    if (zom := ctx.get("m")):
        print("xformed:", zim, "→", zom, file = stderr)
        with zi.open(zim, "r") as zif, zo.open(zom, "w") as zof:
            copyfileobj(zif, zof)
    else:
        print("deleted:", zim, file = stderr)