How to use the reprozip.utils.iteritems function in reprozip

try:
        with manifest.open('wb') as fp:
            fp.write(b'REPROZIP VERSION 2\n')
        tar.add(str(manifest), 'METADATA/version')
    finally:
        manifest.remove()

    # Stores the original trace
    trace = directory / 'trace.sqlite3'
    if not trace.is_file():
        logger.critical("trace.sqlite3 is gone! Aborting")
        sys.exit(1)
    tar.add(str(trace), 'METADATA/trace.sqlite3')

    # Checks that input files are packed
    for name, f in iteritems(inputs_outputs):
        if f.read_runs and not Path(f.path).exists():
            logger.warning("File is designated as input (name %s) but is not "
                           "to be packed: %s", name, f.path)

    # Generates a unique identifier for the pack (for usage reports purposes)
    pack_id = str(uuid.uuid4())

    # Stores canonical config
    fd, can_configfile = Path.tempfile(suffix='.yml', prefix='rpz_config_')
    os.close(fd)
    try:
        save_config(can_configfile, runs, packages, other_files,
                    reprozip_version,
                    inputs_outputs, canonical=True,
                    pack_id=pack_id)

if ' ' not in pkgname:
                        # If we had assigned it to a package already, undo
                        if path in found:
                            found[path] = None
                        # Else assign to the package
                        else:
                            found[path] = pkgname

        # Remaining files are not from packages
        self.unknown_files.update(
            f for f in files
            if f.path in requested and found.get(f.path) is None)

        nb_pkg_files = 0

        for path, pkgname in iteritems(found):
            if pkgname is None:
                continue
            if pkgname in self.packages:
                package = self.packages[pkgname]
            else:
                package = self._create_package(pkgname)
                self.packages[pkgname] = package
            package.add_file(requested.pop(path))
            nb_pkg_files += 1

        logger.info("%d packages with %d files, and %d other files",
                    len(self.packages),
                    nb_pkg_files,
                    len(self.unknown_files))

if pkgname in self.packages:
                        pkgs.append(self.packages[pkgname])
                    else:
                        pkg = self._create_package(pkgname)
                        if pkg is not None:
                            self.packages[pkgname] = pkg
                            pkgs.append(self.packages[pkgname])
                if len(pkgs) == 1:
                    pkgs[0].add_file(f)
                    nb_pkg_files += 1
                else:
                    self.unknown_files.add(f)

        # Filter out packages with no files
        self.packages = {pkgname: pkg
                         for pkgname, pkg in iteritems(self.packages)
                         if pkg.files}

        logger.info("%d packages with %d files, and %d other files",
                    len(self.packages),
                    nb_pkg_files,
                    len(self.unknown_files))

parts = []
                # Run number, if there are more than one runs
                if len(runs) > 1:
                    parts.append(run_nb)
                # Argument number, if there are more than one file arguments
                if nb_file_args[run_nb] > 1:
                    parts.append(arg_nb)
                file_names[fi] = make_unique(
                    'arg%s' % '_'.join('%s' % s for s in parts))
            else:
                file_names[fi] = make_unique('arg_%s' % fi.unicodename)
        else:
            file_names[fi] = make_unique(fi.unicodename)

    return dict((n, InputOutputFile(p, readers.get(p, []), writers.get(p, [])))
                for p, n in iteritems(file_names))

def python(files, input_files, **kwargs):
    add = []
    for path, fi in iteritems(files):
        if path.ext == b'.pyc':
            pyfile = path.parent / path.stem + '.py'
            if pyfile.is_file():
                if pyfile not in files:
                    logger.info("Adding %s", pyfile)
                    add.append(TracedFile(pyfile))

    for fi in add:
        files[fi.path] = fi

    for i in irange(len(input_files)):
        lst = []
        for path in input_files[i]:
            if path.ext in (b'.py', b'.pyc'):
                logger.info("Removing input %s", path)
            else:

parts = []
                # Run number, if there are more than one runs
                if len(runs) > 1:
                    parts.append(run_nb)
                # Argument number, if there are more than one file arguments
                if nb_file_args[run_nb] > 1:
                    parts.append(arg_nb)
                file_names[fi] = make_unique(
                    'arg%s' % '_'.join('%s' % s for s in parts))
            else:
                file_names[fi] = make_unique('arg_%s' % fi.unicodename)
        else:
            file_names[fi] = make_unique(fi.unicodename)

    return dict((n, InputOutputFile(p, readers.get(p, []), writers.get(p, [])))
                for p, n in iteritems(file_names))