# TPU 사용 가능 확인 및 Strategy 설정
try:
    # TPU detection. No parameters necessary if TPU_NAME environment variable is set.
    # On Kaggle this is always the case.
    tpu = (
        tf.distribute.cluster_resolver.TPUClusterResolver()
    )   
    print("Running on TPU ", tpu.master())
except ValueError:
    tpu = None

if tpu:
    tf.config.experimental_connect_to_cluster(tpu)
    tf.tpu.experimental.initialize_tpu_system(tpu)
    strategy = tf.distribute.experimental.TPUStrategy(tpu)
else:
    strategy = (
        tf.distribute.get_strategy()
    )  # default distribution strategy in Tensorflow. Works on CPU and single GPU.

>>> print("REPLICAS: ", strategy.num_replicas_in_sync)
Running on TPU  grpc://10.0.0.2:8470
REPLICAS: 8