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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def generate_or_read_from_file(key_file='.secret_key', key_length=64):
 """Multiprocess-safe secret key file generator. Useful to replace the default (and thus unsafe) SECRET_KEY in settings.py upon first start. Save to use, i.e. when multiple Python interpreters serve the dashboard Django application (e.g. in a mod_wsgi + daemonized environment). Also checks if file permissions are set correctly and throws an exception if not. """

    abspath = os.path.abspath(key_file)
    # check, if key_file already exists
    # if yes, then just read and return key
    if os.path.exists(key_file):
        key = read_from_file(key_file)
        return key

    # otherwise, first lock to make sure only one process
    lock = lockutils.external_lock(key_file + ".lock",
                                   lock_path=os.path.dirname(abspath))
    with lock:
        if not os.path.exists(key_file):
            key = generate_key(key_length)
            old_umask = os.umask(0o177)  # Use '0600' file permissions
            with open(key_file, 'w') as f:
                f.write(key)
            os.umask(old_umask)
        else:
            key = read_from_file(key_file)
        return key