How to check if file exists in Google Cloud Storage?

Question

I have a script where I want to check if a file exists in a bucket and if it doesn't then create one.

I tried using os.path.exists(file_path) where file_path = "/gs/testbucket", but I got a file not found error.

I know that I can use the files.listdir() API function to list all the files located at a path and then check if the file I want is one of them. But I was wondering whether there is another way to check whether the file exists.

Answer 1

This post is old, you can actually now check if a file exists on GCP using the blob class, but because it took me a while to find an answer, adding here for the others who are looking for a solution

from google.cloud import storage

name = 'file_i_want_to_check.txt'   
storage_client = storage.Client()
bucket_name = 'my_bucket_name'
bucket = storage_client.bucket(bucket_name)
stats = storage.Blob(bucket=bucket, name=name).exists(storage_client)

Documentation is here

Hope this helps!

Edit

As per the comment by @om-prakash, if the file is in a folder, then the name should include the path to the file:

name = "folder/path_to/file_i_want_to_check.txt"

Answer 2

It's as easy as use the exists method within a blob object:

from google.cloud import storage

def blob_exists(projectname, credentials, bucket_name, filename):
   client = storage.Client(projectname, credentials=credentials)
   bucket = client.get_bucket(bucket_name)
   blob = bucket.blob(filename)
   return blob.exists()

Answer 3

The answer provided by @nickthefreak is correct, and so is the comment by Om Prakash. One other note is that the bucket_name should not include gs:// in front or a / at the end.

Piggybacking off @nickthefreak's example and Om Prakash's comment:

from google.cloud import storage

name = 'folder1/another_folder/file_i_want_to_check.txt'   

storage_client = storage.Client()
bucket_name = 'my_bucket_name'  # Do not put 'gs://my_bucket_name'
bucket = storage_client.bucket(bucket_name)
stats = storage.Blob(bucket=bucket, name=name).exists(storage_client)

stats will be a Boolean (True or False) depending on whether the file exists in the Storage Bucket.

(I don't have enough reputation points to comment, but I wanted to save other people some time because I wasted way too much time with this).