'Bookkeeping after installation: interpret any new .pth files that have
appeared'

def afterInstall(self):

    new_contents = os.listdir(self._db.preferences.installDir)
    for fn in new_contents:
        if (fn in self._old_contents):
            continue
        if (fn[(-4):] != '.pth'):
            continue
        fullname = os.path.join(self._db.preferences.installDir, fn)
        f = open(fullname)
        for line in f.readlines():
            if (not line):
                continue
            if (line[0] == '#'):
                continue
            if (line[:6] == 'import'):
                exec line
                continue
            if (line[(-1)] == '\n'):
                line = line[:(-1)]
            if (not os.path.isabs(line)):
                line = os.path.join(self._db.preferences.installDir, line)
            line = os.path.realpath(line)
            if (not (line in sys.path)):
                sys.path.append(line)
