Python Google Drive API file download showing success but files not saved locally

Other Questions Google drive
1

I’m working on a Python script to download files from Google Drive using their API with OAuth authentication. The authentication seems to work fine, and my code runs without any errors. It even shows download progress reaching 100%, but I can’t find the actual files on my local machine afterward.

Here’s my first attempt at downloading:

def fetch_drive_file(item_id, content_type):
    if "google-apps" in content_type:
        return
    file_request = drive_client.files().get(fileId=item_id)
    buffer = io.BytesIO()
    file_downloader = MediaIoBaseDownload(buffer, file_request)
    completed = False
    while not completed:
        progress, completed = file_downloader.next_chunk()
        print "Progress: %d%%" % int(progress.progress() * 100)

This prints “Progress: 100%” but no actual file appears on my system.

I also tried this alternative approach:

def get_file_content(file_url):
    response, data = drive_client._http.request(file_url)
    if response.status == 200:
        print 'Response: %s' % response
        return data
    else:
        print 'Error occurred: %s' % response
        return None

This method also returns a successful 200 status but still no file gets saved locally.

Both methods seem to communicate with the API correctly. What am I missing to actually save these files to my computer? Do I need an extra step to write the downloaded content to disk?

2

Yeah, this tripped me up too when I started with the Drive API. You’re downloading to memory but not actually saving it anywhere. Add buffer.seek(0) then write the buffer contents to a file with whatever name you want. The 100% progress just means the download to RAM finished successfully.

3

Indeed, your code downloads the file data into memory, but it doesn’t save it to disk. The BytesIO buffer holds all the download content, which is essentially unused unless you write it out. You should retrieve the filename from the API response and then write the buffer content to a file accordingly. Here’s a concise way to implement this fix:

file_metadata = drive_client.files().get(fileId=item_id).execute()
filename = file_metadata['name']
# ... your existing download code ...
with open(filename, 'wb') as output_file:
    output_file.write(buffer.getvalue())

I faced a similar problem in the past while working with the Drive API. It can be misleading, as the documentation doesn’t explicitly mention the necessity of additional steps for saving the downloaded content.

4

You’re downloading the file data but not actually writing it to disk. Your first method stores everything in the BytesIO buffer, but you need to pull it out and save it. After your download loop, add this:

buffer.seek(0)
with open('downloaded_file.ext', 'wb') as f:
    f.write(buffer.read())

Same deal with your second method - the ‘data’ variable has your file content, just write it out the same way. I made this exact mistake when I started with the Drive API. Spent hours confused why downloads worked but no files showed up anywhere. The API grabs everything into memory, but Python won’t save it unless you tell it to.