The get_bucket_location() method is used to return the region in which the bucket resides.
If a region was specified in the CreateBucket() request, it is returned by this method. If no region was specified in the CreateBucket() request, the bucket region was set to 'vast-1', which is returned by this method.
Example
response = s3_client.get_bucket_location(
Bucket='mybucket',
)