Google Cloud Storage List Directories in Python

gcs_list_folders.py

def gcs_list_folders(bucket, prefix="", delimeter="/", guess_lexicographically_last_item="~", gcs_client=None):
    folders = set()
    prefix_parts = prefix.split(delimeter)
    start_offset = "/".join(prefix_parts)
    last_blob_name = None
    while True:
        blobs = list(gcs_client.list_blobs(
            bucket_or_name=bucket,
            prefix=prefix,
            start_offset=start_offset,
            max_results=1
        ))
        if not blobs:
            break
        blob = blobs[0]
        if last_blob_name == blob.name:
            raise Exception("Saw blob {} twice, try setting a different guess_lexicographically_last_item={}.".format(
                repr(blob.name), repr(guess_lexicographically_last_item)
            ))
        folder = delimeter.join(blob.name.split(delimeter)[0:len(prefix_parts)] + [""])
        folders.add(folder)
        start_offset = folder + guess_lexicographically_last_item
        last_blob_name = blob.name
        try_characters = 1

    return folders
    
from google.cloud.storage.client import Client

gcs_client = Client()

print(gcs_list_folders(bucket="my-bucket", gcs_client=gcs_client))
print(gcs_list_folders(bucket="my-bucket", prefix="foo/", gcs_client=gcs_client))
print(gcs_list_folders(bucket="my-bucket", prefix="foo/bar/", gcs_client=gcs_client))