fix(example): move python code into __main__ (#350)

Co-authored-by: songjunjie <[email protected]>

examples/simple_example.py

@@ -2,24 +2,25 @@
 import shutil
 import os
 
-output_dir = os.path.abspath("bench")
+if __name__ == '__main__':
+    output_dir = os.path.abspath("bench")
 
-if os.path.exists(output_dir):
-    shutil.rmtree(output_dir)
+    if os.path.exists(output_dir):
+        shutil.rmtree(output_dir)
 
-download(
-    processes_count=16,
-    thread_count=32,
-    url_list="../tests/test_files/test_10000.parquet",
-    image_size=256,
-    output_folder=output_dir,
-    output_format="files",
-    input_format="parquet",
-    url_col="URL",
-    caption_col="TEXT",
-    enable_wandb=True,
-    number_sample_per_shard=1000,
-    distributor="multiprocessing",
-)
+    download(
+        processes_count=16,
+        thread_count=32,
+        url_list="../tests/test_files/test_10000.parquet",
+        image_size=256,
+        output_folder=output_dir,
+        output_format="files",
+        input_format="parquet",
+        url_col="URL",
+        caption_col="TEXT",
+        enable_wandb=True,
+        number_sample_per_shard=1000,
+        distributor="multiprocessing",
+    )
 
-# rm -rf bench
+    # rm -rf bench