Azure-sdk-for-python: "exists" operator for containers and blobs

[subesokun]

Add exists operator to ContainerClient and BlobClient to verify if the given container or blob is existing.

container_client = blob_service_client.get_container_client("mycontainer")
container_client.exists()

blob_container_client = container_client.get_blob_client("myblob")
blob_container_client.exists()

See related feature request for azure-sdk-for-js https://github.com/Azure/azure-sdk-for-js/issues/5062

[kaerm]

Hi @subesokun thank you for letting us know, we will look into this //cc: @rakshith91 @mayurid

[rakshith91]

Hi @subesokun
Thanks for reporting. While we discuss this feature, you can do the following if you are blocked because of it

from azure.core.exceptions import ResourceNotFoundError

try:
    # somethhing with blob/container
except ResourceNotFoundError:
    pass

[subesokun]

@rakshith91 Thanks for the hint! This is a bit off-topic, but is there any documentation available that tells me which exceptions can be thrown by a certain function call? That would've helped me a lot to figure out on my own that e.g. ResourceNotFoundError gets thrown when accessing a none existing blob.

[xiafu-msft]

Hi @subesokun
Sorry about the late response.
You can map the http status code according to this chart, it would help you debug.
All of the exceptions are children of StorageErrorException

[msftbot[bot]]

Thanks for the feedback! We are routing this to the appropriate team for follow-up. cc @xgithubtriage.

[chrisyeh96]

Are there any updates on this? I would really appreciate a BlobClient.exists() method for checking if a blob exists within a given container, especially since this was a feature in v2.1 of the Azure Python SDK.

For the record, here's what I currently am doing to check for whether a blob exists, but it's far more verbose than it really should be.

from azure.storage.blob import BlobClient
from azure.core.exceptions import ResourceNotFoundError

def exists(blob_url: str) -> bool:
    blob_client = BlobClient.from_blob_url(blob_url)
    try:
        blob_client.get_blob_properties()
    except ResourceNotFoundError:
        return False
    return True

valid_blob_uri = "https://lilablobssc.blob.core.windows.net/nacti-unzipped/part0/sub000/2010_Unit150_Ivan097_img0003.jpg"
invalid_blob_uri = "https://lilablobssc.blob.core.windows.net/nacti-unzipped/part0/sub000/2010_Unit150_Ivan000_img0003.jpg"

assert exists(valid_blob_uri)
assert not exists(invalid_blob_uri)

[xiafu-msft]

Hi @chrisyeh96
We have a pr to add blob exists() and it should be released soon this is the duplicate issue https://github.com/Azure/azure-sdk-for-python/issues/12744