Boto s3 download file example wait exists

Having to create a new HTTPS connection and adding it to the pool costs time, but what if we disregard that and compare the two functions "purely" on how long they take when the file does NOT exist? Remember, the second measurement above was when every object exists. So we know it took 0. How long does it take to figure out that the object does not exist independent of any other op. That means we avoid the bug so the comparison is fair. The client. And it matters. That's because the time difference when it always finds the object was 0.

When it comes to figuring out that the object did not exist the time difference is 0. That's still a pretty small number but, hey, you gotto draw the line somewhere. Using client. If you think you'll often find that the object doesn't exist and needs a client. If you think you'll rarely need client. Follow peterbe on Twitter. I just searching for the solution. I think list object is not matching for buckets with large amount of files. What makes you think that?

ClientError we need to install botocore. This is particularly impacting if we use aws lambda functions. In place of that if we just use exception then we can skip using the extra library! Here is a solution that works for me. One caveat is that I know the exact format of the key ahead of time, so I am only listing the single file. Just following the thread, can someone conclude which one is the most efficient way to check if an object exists in S3?

Check to see if a particular key exists within the bucket. This method uses a HEAD request to check for the existence of the key. Returns: An instance of a Key object or None. If the error code is than False is returned.

Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Collectives on Stack Overflow. Learn more. Asked 6 years ago. Active 29 days ago. Viewed k times. But that seems longer and an overkill. Boto3 official docs explicitly state how to do this. May be I am missing the obvious. Can anybody point me how I can achieve this.

Improve this question. Prabhakar Shanmugam Prabhakar Shanmugam 4, 5 5 gold badges 22 22 silver badges 32 32 bronze badges. Add a comment. Active Oldest Votes. Object 'my-bucket', 'dootdoot. ClientError as e: if e. Improve this answer. Wander Nauta Wander Nauta Thanks for the quick reply Wander.

I just need the same for boto3. I withdraw my suggestion. On boto3 version 1. I haven't checked whether this is due to a difference in library versions or a change in the API itself since this answer was written. Either way, in my version of boto3, a shorter approach than checking e. NoSuchKey in the first place. Show 12 more comments. The easiest way I found and probably the most efficient is this: import boto3 from botocore. Alan W. Smith You can also give a name that is different from the object name.

If your file is existing as a. Including the sub folders in your s3 Bucket. If you have any issues, you can also comment below to ask a question. Spread the knowledge by sharing : 0 More. Share via. Copy Link. Resources must have at least one identifier, except for the top-level service resources e. An identifier is set at instance creation-time, and failing to provide all necessary identifiers during instantiation will result in an exception.

Examples of identifiers:. Identifiers also play a role in resource instance equality. For two instances of a resource to be considered equal, their identifiers must be equal:. Only identifiers are taken into account for instance equality.

Region, account ID and other data members are not considered. When using temporary credentials or multiple regions in your code please keep this in mind. Resources may also have attributes, which are lazy-loaded properties on the instance. They may be set at creation time from the response of an action on another resource, or they may be set when accessed or via an explicit call to the load or reload action. Examples of attributes:.

Attributes may incur a load action when first accessed. If latency is a concern, then manually calling load will allow you to control exactly when the load action and thus latency is invoked. The documentation for each resource explicitly lists its attributes. Additionally, attributes may be reloaded after an action has been performed on the resource. An action is a method which makes a call to the service.