How do I quickly get data out of a Google Cloud Datalab notebook?

Question

I just want to grab some output data from a Google Cloud Datalab notebook quickly, preferably as a throwaway CSV file.

I've done this:

writer = csv.writer(open('output.csv', 'wb'))
for row in rows:
    writer.writerow(row)

This writes a local file, but then I can't either open it in the browser, or (see how to) download it from Cloud Datalab.

How can I quickly grab my data as a CSV file? I guess maybe I have to use the Storage APIs and write it ? I'm finding the docs a bit hard to follow, I've got something like this:

import gcp
import gcp.storage as storage

// create CSV file? construct filepath? how?

mybucket = storage.Bucket(myfile)
mybucket.create()

Answer 1

There are at least 2 options:

Download files locally from Datalab

This option does not appear to be available in the current Datalab code. I have submitted a pull request for Datalab which may resolve your issue. The fix allows users to edit/download files which are not notebooks (*.ipynb) using the Datalab interface. I was able to download/edit a text file from Datalab using the modification in the pull request.

Send files to a Storage Bucket in Google Cloud

The following link may be helpful in writing code to transfer files to a storage bucket in Google Cloud using the Storage API.

Here is a working example:

from datalab.context import Context
import datalab.storage as storage

sample_bucket_name = Context.default().project_id + '-datalab-example'
sample_bucket_path = 'gs://' + sample_bucket_name

sample_bucket = storage.Bucket(sample_bucket_name)

# Create storage bucket if it does not exist
if not sample_bucket.exists():
    sample_bucket.create()

# Write an item to the storage bucket
sample_item = sample_bucket.item('stringtofile.txt')
sample_item.write_to('This is a string', 'text/plain')

# Another way to copy an item from Datalab to Storage Bucket
!gsutil cp 'someotherfile.txt' sample_bucket_path

Once you've copied an item, click here to view the item in a Storage Bucket in Google Cloud