python - Uploading files using Browse Button in Jupyter and Using/Saving them

Question

I came across this snippet for uploading files in Jupyter however I don't know how to save this file on the machine that executes the code or how to show the first 5 lines of the uploaded file. Basically I am looking for proper commands for accessing the file after it has been uploaded:

import io
from IPython.display import display
import fileupload

def _upload():

    _upload_widget = fileupload.FileUploadWidget()

    def _cb(change):
        decoded = io.StringIO(change['owner'].data.decode('utf-8'))
        filename = change['owner'].filename
        print('Uploaded `{}` ({:.2f} kB)'.format(
            filename, len(decoded.read()) / 2 **10))

    _upload_widget.observe(_cb, names='data')
    display(_upload_widget)

_upload()

Answer 1

_cb is called when the upload finishes. As described in the comment above, you can write to a file there, or store it in a variable. For example:

from IPython.display import display
import fileupload

uploader = fileupload.FileUploadWidget()

def _handle_upload(change):
    w = change['owner']
    with open(w.filename, 'wb') as f:
        f.write(w.data)
    print('Uploaded `{}` ({:.2f} kB)'.format(
        w.filename, len(w.data) / 2**10))

uploader.observe(_handle_upload, names='data')

display(uploader)

After the upload has finished, you can access the filename as:

uploader.filename