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Showing posts with label developer. Show all posts
Showing posts with label developer. Show all posts

Thursday, June 1, 2017

Managing Shared (formerly Team) Drives with Python and the Google Drive API

2023 UPDATE: We are working to put updated versions of all the code into GitHub... stay tuned. The link will provided in all posts once the code sample(s) is(are) available.

2019 UPDATE: "G Suite" is now called "Google Workspace", "Team Drives" is now known as "Shared Drives", and the corresponding supportsTeamDrives flag has been renamed to supportsAllDrives. Please take note of these changes regarding the post below.

NOTE 1: Team Drives is only available for G Suite Business Standard users or higher. If you're developing an application for Team Drives, you'll need similar access.
NOTE 2: The code featured here is also available as a video + overview post as part of this series.

Introduction

Team Drives is a relatively new feature from the Google Drive team, created to solve some of the issues of a user-centric system in larger organizations. Team Drives are owned by an organization rather than a user and with its use, locations of files and folders won't be a mystery any more. While your users do have to be a G Suite Business (or higher) customer to use Team Drives, the good news for developers is that you won't have to write new apps from scratch or learn a completely different API.

Instead, Team Drives features are accessible through the same Google Drive API you've come to know so well with Python. In this post, we'll demonstrate a sample Python app that performs core features that all developers should be familiar with. By the time you've finished reading this post and the sample app, you should know how to:
  • Create Team Drives
  • Add members to Team Drives
  • Create a folder in Team Drives
  • Import/upload files to Team Drives folders

Using the Google Drive API

The demo script requires creating files and folders, so you do need full read-write access to Google Drive. The scope you need for that is:
  • 'https://www.googleapis.com/auth/drive' — Full (read-write) access to Google Drive
If you're new to using Google APIs, we recommend reviewing earlier posts & videos covering the setting up projects and the authorization boilerplate so that we can focus on the main app. Once we've authorized our app, assume you have a service endpoint to the API and have assigned it to the DRIVE variable.

Create Team Drives

New Team Drives can be created with DRIVE.teamdrives().create(). Two things are required to create a Team Drive: 1) you should name your Team Drive. To make the create process idempotent, you need to create a unique request ID so that any number of identical calls will still only result in a single Team Drive being created. It's recommended that developers use a language-specific UUID library. For Python developers, that's the uuid module. From the API response, we return the new Team Drive's ID. Check it out:
def create_td(td_name):
    request_id = str(uuid.uuid4())
    body = {'name': td_name}
    return DRIVE.teamdrives().create(body=body,
            requestId=request_id, fields='id').execute().get('id')

Add members to Team Drives

To add members/users to Team Drives, you only need to create a new permission, which can be done with  DRIVE.permissions().create(), similar to how you would share a file in regular Drive with another user.  The pieces of information you need for this request are the ID of the Team Drive, the new member's email address as well as the desired role... choose from: "organizer", "owner", "writer", "commenter", "reader". Here's the code:
def add_user(td_id, user, role='commenter'):
    body = {'type': 'user', 'role': role, 'emailAddress': user}
    return DRIVE.permissions().create(body=body, fileId=td_id,
            supportsTeamDrives=True, fields='id').execute().get('id')
Some additional notes on permissions: the user can only be bestowed permissions equal to or less than the person/admin running the script... IOW, they cannot grant someone else greater permission than what they have. Also, if a user has a certain role in a Team Drive, they can be granted greater access to individual elements in the Team Drive. Users who are not members of a Team Drive can still be granted access to Team Drive contents on a per-file basis.

Create a folder in Team Drives

Nothing to see here! Yep, creating a folder in Team Drives is identical to creating a folder in regular Drive, with DRIVE.files().create(). The only difference is that you pass in a Team Drive ID rather than regular Drive folder ID. Of course, you also need a folder name too. Here's the code:
def create_td_folder(td_id, folder):
    body = {'name': folder, 'mimeType': FOLDER_MIME, 'parents': [td_id]}
    return DRIVE.files().create(body=body,
            supportsTeamDrives=True, fields='id').execute().get('id')

Import/upload files to Team Drives folders

Uploading files to a Team Drives folder is also identical to to uploading to a normal Drive folder, and also done with DRIVE.files().create(). Importing is slightly different than uploading because you're uploading a file and converting it to a G Suite/Google Apps document format, i.e., uploading CSV as a Google Sheet, or plain text or Microsoft Word® file as Google Docs. In the sample app, we tackle the former:
def import_csv_to_td_folder(folder_id, fn, mimeType):
    body = {'name': fn, 'mimeType': mimeType, 'parents': [folder_id]}
    return DRIVE.files().create(body=body, media_body=fn+'.csv',
            supportsTeamDrives=True, fields='id').execute().get('id')
The secret to importing is the MIMEtype. That tells Drive whether you want conversion to a G Suite/Google Apps format (or not). The same is true for exporting. The import and export MIMEtypes supported by the Google Drive API can be found in my SO answer here.

Driver app

All these functions are great but kind-of useless without being called by a main application, so here we are:
FOLDER_MIME = 'application/vnd.google-apps.folder'
SOURCE_FILE = 'inventory' # on disk as 'inventory.csv'
SHEETS_MIME = 'application/vnd.google-apps.spreadsheet'

td_id = create_td('Corporate shared TD')
print('** Team Drive created')
perm_id = add_user(td_id, 'email@example.com')
print('** User added to Team Drive')
folder_id = create_td_folder(td_id, 'Manufacturing data')
print('** Folder created in Team Drive')
file_id = import_csv_to_td_folder(folder_id, SOURCE_FILE, SHEETS_MIME)
print('** CSV file imported as Google Sheets in Team Drives folder')
The first set of variables represent some MIMEtypes we need to use as well as the CSV file we're uploading to Drive and requesting it be converted to Google Sheets format. Below those definitions are calls to all four functions described above.

Conclusion

If you run the script, you should get output that looks something like this, with each print() representing each API call:
$ python3 td_demo.py
** Team Drive created
** User added to Team Drive
** Folder created in Team Drive
** CSV file imported as Google Sheets in Team Drives folder
When the script has completed, you should have a new Team Drives folder called "Corporate shared TD", and within, a folder named "Manufacturing data" which contains a Google Sheets file called "inventory".

Below is the entire script for your convenience which runs on both Python 2 and Python 3 (unmodified!)—by using, copying, and/or modifying this code or any other piece of source from this blog, you implicitly agree to its Apache2 license:
from __future__ import print_function
import uuid

from apiclient import discovery
from httplib2 import Http
from oauth2client import file, client, tools

SCOPES = 'https://www.googleapis.com/auth/drive'
store = file.Storage('storage.json')
creds = store.get()
if not creds or creds.invalid:
    flow = client.flow_from_clientsecrets('client_secret.json', SCOPES)
    creds = tools.run_flow(flow, store)
DRIVE = discovery.build('drive', 'v3', http=creds.authorize(Http()))

def create_td(td_name):
    request_id = str(uuid.uuid4()) # random unique UUID string
    body = {'name': td_name}
    return DRIVE.teamdrives().create(body=body,
            requestId=request_id, fields='id').execute().get('id')

def add_user(td_id, user, role='commenter'):
    body = {'type': 'user', 'role': role, 'emailAddress': user}
    return DRIVE.permissions().create(body=body, fileId=td_id,
            supportsTeamDrives=True, fields='id').execute().get('id')

def create_td_folder(td_id, folder):
    body = {'name': folder, 'mimeType': FOLDER_MIME, 'parents': [td_id]}
    return DRIVE.files().create(body=body,
            supportsTeamDrives=True, fields='id').execute().get('id')

def import_csv_to_td_folder(folder_id, fn, mimeType):
    body = {'name': fn, 'mimeType': mimeType, 'parents': [folder_id]}
    return DRIVE.files().create(body=body, media_body=fn+'.csv',
            supportsTeamDrives=True, fields='id').execute().get('id')

FOLDER_MIME = 'application/vnd.google-apps.folder'
SOURCE_FILE = 'inventory' # on disk as 'inventory.csv'... CHANGE!
SHEETS_MIME = 'application/vnd.google-apps.spreadsheet'

td_id = create_td('Corporate shared TD')
print('** Team Drive created')
perm_id = add_user(td_id, 'email@example.com') # CHANGE!
print('** User added to Team Drive')
folder_id = create_td_folder(td_id, 'Manufacturing data')
print('** Folder created in Team Drive')
file_id = import_csv_to_td_folder(folder_id, SOURCE_FILE, SHEETS_MIME)
print('** CSV file imported as Google Sheets in Team Drives folder')
As with our other code samples, you can now customize it to learn more about the API, integrate into other apps for your own needs, for a mobile frontend, sysadmin script, or a server-side backend!

Code challenge

Write a simple application that moves folders (and its files or folders) in regular Drive to Team Drives. Each folder you move should be a corresponding folder in Team Drives. Remember that files in Team Drives can only have one parent, and the same goes for folders.

Monday, July 11, 2016

Exporting a Google Sheet spreadsheet as CSV

Introduction

Today, we'll follow-up to my earlier post on the Google Sheets API and multiple posts (first, secondthird) on the Google Drive API by answering one common question: How do you download a Google Sheets spreadsheet as a CSV file? The "FAQ"ness of the question itself as well as various versions of Google APIs has led to many similar StackOverflow questions: one, two, three, four, five, just to list a few. Let's answer this question definitively and walk through a Python code sample that does exactly that. The main assumption is that you have a Google Sheet file in your Google Drive named "inventory".

Choosing the right API

Upon first glance, developers may think the Google Sheets API is the one to use. Unfortunately that isn't the case. The Sheets API is the one to use for spreadsheet-oriented operations, such as inserting data, reading spreadsheet rows, managing individual tab/sheets within a spreadsheet, cell formatting, creating charts, adding pivot tables, etc., It isn't meant to perform file-based requests like exporting a Sheet in CSV (comma-separated values) format. For file-oriented operations with a Google Sheet, you would use the Google Drive API.

Using the Google Drive API

As mentioned earlier, Google Drive features numerous API scopes of authorization. As usual, we always recommend you use the most restrictive scope possible that allows your app to do its work. You'll request fewer permissions from your users (which makes them happier), and it also makes your app more secure, possibly preventing modifying, destroying, or corrupting data, or perhaps inadvertently going over quotas. Since we're only exporting a Google Sheets file from Google Drive, the only scope we need is:
  • 'https://www.googleapis.com/auth/drive.readonly' — Read-only access to file content or metadata
The earlier post I wrote on the Google Drive API featured sample code that exported an uploaded Google Docs file as PDF and download that from Drive. This post will not only feature a change to exporting a Google Sheets file in CSV format, but also demonstrate one additional feature of the Drive API: querying

Since we've fully covered the authorization boilerplate fully in earlier posts and videos, we're going to skip that here and jump right to the action, creating of a service endpoint to Drive. The API name is (of course 'drive', and the current version of the API is 3, so use the string 'v3' in this call to the apiclient.discovey.build() function:

DRIVE = discovery.build('drive', 'v3', http=creds.authorize(Http()))

Query and export files from Google Drive

While unnecessary, we'll create a few string constants representing the filename, source and destination file MIME types to make the code easier to understand:
FILENAME = 'inventory'
SRC_MIMETYPE = 'application/vnd.google-apps.spreadsheet'
DST_MIMETYPE = 'text/csv'
In this simple example, we're only going to export one Google Sheets file as CSV, arbitrarily choosing a file named, "inventory." So to perform the query, you need both the filename and its MIME type, "application/vnd.google-apps.spreadsheet". Query components are conjoined with the "and" keyword, so your query string will look like this: q='name="%s" and mimeType="%s"' % (FILENAME, SRC_MIMETYPE).

Since there may be more than one Google Sheets file named 'inventory". we opt for newest one and thus need to sort all matching files in descending order of last modification time then name if "mtime"s are identical via an "order by" clause: orderBy='modifiedTime desc,name'. Here is the complete call to DRIVE.files().list() to issue the query:
files = DRIVE.files().list(
    q='name="%s" and mimeType="%s"' % (FILENAME, SRC_MIMETYPE),
    orderBy='modifiedTime desc,name').execute().get('files', [])
If any files match, the payload will contain a 'files' key, else we default to an empty list and display to the user on the last line that no files were found. Otherwise, grab the first match, the most recently-modified 'inventory' file, create a suitable CSV filename from it, and change all spaces to underscores:

fn = '%s.csv' % os.path.splitext(files[0]['name'].replace(' ', '_'))[0]

The final Drive API call requests an export of 'inventory' as a CSV file, and if successful, the downloaded data is written with the filename above. In either case, the user is notified of success or failure of the export:
data = DRIVE.files().export(fileId=files[0]['id'], mimeType=DST_MIMETYPE).execute()
if data:
    with open(fn, 'wb') as f:
        f.write(data)
    print('DONE')
else:
    print('ERROR (could not download file)')
Note that if downloading as CSV, the Drive API only exports of the first sheet in a Sheets file... you won't get any others. However, it does support 3 other download formats that will get you all the sheets.

If you create a Sheets file named 'inventory', run the script, grant the script access to your Google Drive (via the OAuth2 prompt that pops up in the browser), and then you should get output that looks like this:
$ python drive_sheets_csv_export.py # or python3
Exporting "inventory" as "inventory.csv"... DONE

Conclusion

Below is the entire script for your convenience which runs on both Python 2 and Python 3 (unmodified!). If I were to divide the script into 4 major sections, they would be:
  • Get creds & build Google Drive service endpoint
  • Source and destination file info
  • Query Google Drive for matching files
  • Export most recent matching Sheets file as CSV

Here's the code itself:
from __future__ import print_function
import os

from apiclient import discovery
from httplib2 import Http
from oauth2client import file, client, tools

SCOPES = 'https://www.googleapis.com/auth/drive.readonly'
store = file.Storage('storage.json')
creds = store.get()
if not creds or creds.invalid:
    flow = client.flow_from_clientsecrets('client_secret.json', SCOPES)
    creds = tools.run_flow(flow, store)
DRIVE = discovery.build('drive', 'v3', http=creds.authorize(Http()))

FILENAME = 'inventory'
SRC_MIMETYPE = 'application/vnd.google-apps.spreadsheet'
DST_MIMETYPE = 'text/csv'

files = DRIVE.files().list(
    q='name="%s" and mimeType="%s"' % (FILENAME, SRC_MIMETYPE),
    orderBy='modifiedTime desc,name').execute().get('files', [])

if files:
    fn = '%s.csv' % os.path.splitext(files[0]['name'].replace(' ', '_'))[0]
    print('Exporting "%s" as "%s"... ' % (files[0]['name'], fn), end='')
    data = DRIVE.files().export(fileId=files[0]['id'], mimeType=DST_MIMETYPE).execute()
    if data:
        with open(fn, 'wb') as f:
            f.write(data)
        print('DONE')
    else:
        print('ERROR (could not download file)')
else:
    print('!!! ERROR: File not found')
As with our other code samples, you can now customize for your own needs, for a mobile frontend, sysadmin script, or a server-side backend, perhaps accessing other Google APIs. Hope this helps answer yet another frequently asked question!

Wednesday, December 23, 2015

Migrating to Google Drive API v3

NOTE: The code covered in this and the previous post are also available in a video walkthrough. Mar 2018 UPDATE: Modernized the code a bit, shortening it, and changed to R/W scope because drive.file doesn't work if the file hasn't been created yet. The same fixes were made to the Drive API v2 sample in the preceding blog post.

Introduction

In a blog post last week, we introduced readers to performing uploads and downloads files to/from Google Drive from a simple Python command-line script. In an official Google blog post later that same day, the Google Drive API team announced a new version of the API. Great timing huh? Well, good thing I knew it was coming, so that I could prepare this post for you, which is a primer on how to migrate from the current version of the API (v2) to the new one (v3).

As stated by the Drive team, v2 isn't being deprecated, and there are no new features in v3, thus migration isn't required. The new version is mainly for new apps/integrations as well as developers with v2 apps who wish to take advantage of the improvements. This post is intended for those in the latter group, covering porting existing apps to v3. Ready? Let's go straight to the action.

Migrating from Google Drive API v2 to v3

Most of this post will be just examining all the "diffs" between the v2 code sample from the previous post (renamed from drive_updown.py to drive_updown2.py) and its v3 equivalent (drive_updown3.py). We'll take things step-by-step to provide more details, but let's start with all the diffs first:
--- drive_updown2.py   2018-03-11 21:42:33.000000000 -0700
+++ drive_updown3.py   2018-03-11 21:44:57.000000000 -0700
@@ -11,23 +11,24 @@
 if not creds or creds.invalid:
     flow = client.flow_from_clientsecrets('client_secret.json', SCOPES)
     creds = tools.run_flow(flow, store)
-DRIVE = discovery.build('drive', 'v2', http=creds.authorize(Http()))
+DRIVE = discovery.build('drive', 'v3', http=creds.authorize(Http()))
 
 FILES = (
-    ('hello.txt', False),
-    ('hello.txt', True),
+    ('hello.txt', None),
+    ('hello.txt', 'application/vnd.google-apps.document'),
 )
 
-for filename, convert in FILES:
-    metadata = {'title': filename}
-    res = DRIVE.files().insert(convert=convert, body=metadata,
-            media_body=filename, fields='mimeType,exportLinks').execute()
+for filename, mimeType in FILES:
+    metadata = {'name': filename}
+    if mimeType:
+        metadata['mimeType'] = mimeType
+    res = DRIVE.files().create(body=metadata, media_body=filename).execute()
     if res:
         print('Uploaded "%s" (%s)' % (filename, res['mimeType']))
 
 if res:
     MIMETYPE = 'application/pdf'
-    res, data = DRIVE._http.request(res['exportLinks'][MIMETYPE])
+    data = DRIVE.files().export(fileId=res['id'], mimeType=MIMETYPE).execute()
     if data:
         fn = '%s.pdf' % os.path.splitext(filename)[0]
         with open(fn, 'wb') as fh:
We'll start with the building of the service endpoint, with the trivial change of the API version string from 'v2' to 'v3':
-DRIVE = build('drive', 'v2', http=creds.authorize(Http()))
+DRIVE = build('drive', 'v3', http=creds.authorize(Http()))
The next change is the deprecation of the conversion flag. The problem with a Boolean variable is that it limits the possible types of file formats supported. By changing it to a file mimeType instead, the horizons are broadened:
 FILES = (
-    ('hello.txt', False),
-    ('hello.txt', True),
+    ('hello.txt', None),
+    ('hello.txt', 'application/vnd.google-apps.document'),
 )
Your next question will be: "What are the mimeTypes for the supported Google Apps document formats?" The answers can be found at this page in the official docs. This changes the datatype in our array of 2-tuples, so we need to change the loop variable to reflect this... we'll use the mimeType instead of a conversion flag:
-for filename, convert in FILES:
+for filename, mimeType in FILES:
Another change related to deprecating the convert flag is that the mimeType isn't a parameter to the API call. Instead, it's another piece of metadata, so we need to add mimeType to the metadata object.

Related to this is a name change: since a file's name is its name and not its title, it makes more sense to use "name" as the metadata value:
-    metadata = {'title': filename}
+    metadata = {'name': filename}
+    if mimeType:
+        metadata['mimeType'] = mimeType
Why the if statement? Not only did v3 see a change to using mimeTypes, but rather than being a parameter like the conversion flag in v2, the mimeType has been moved into the file's metadata, so if we're doing any conversion, we need to add it to our metadata field (then remove the convert parameter down below).

Next is yet another name change: when creating files on Google Drive, "create()" makes more sense as a method name than "insert()". Reducing the size of payload is another key ingredient of v3. We mentioned in the previous post that insert() returns more than 30 fields in the response payload unless you use the fields parameter to specify exactly which you wish returned. In v3, the default response payload only returns four fields, including all the ones we need in this script, so use of the fields parameter isn't required any more:
-    res = DRIVE.files().insert(convert=convert, body=metadata,
-            media_body=filename, fields='mimeType,exportLinks').execute()
+    res = DRIVE.files().create(body=metadata, media_body=filename).execute()
The final improvement we can demonstrate: users no longer have to make an authorized HTTP GET request with a link to export and download a file in an alternate format like PDF®. Instead, it's now a "normal" API call (to the new "export()" method) with the mimeType as a parameter. The only other parameter you need is the file ID, which comes back as part of the (default) response payload when the create() call was made:
-    res, data = DRIVE._http.request(res['exportLinks'][MIMETYPE])
+    data = DRIVE.files().export(fileId=res['id'], mimeType=MIMETYPE).execute()
That's it! If you run the script, grant the script access to your Google Drive (via the OAuth2 prompt that pops up in the browser), and then you should get output that looks like this:
$ python drive_updown3.py # or python3
Uploaded "hello.txt" (text/plain)
Uploaded "hello.txt" (application/vnd.google-apps.document)
Downloaded "hello.pdf" (application/pdf)

Conclusion

The entire v2 script (drive_updown2.py) was spelled out in full in the previous post, and it hasn't changed since then. Below is the v3 script (drive_updown3.py) for your convenience which runs on both Python 2 and Python 3 (unmodified!):
#!/usr/bin/env python

from __future__ import print_function
import os

from apiclient import discovery
from httplib2 import Http
from oauth2client import file, client, tools

SCOPES = 'https://www.googleapis.com/auth/drive'
store = file.Storage('storage.json')
creds = store.get()
if not creds or creds.invalid:
    flow = client.flow_from_clientsecrets('client_secret.json', SCOPES)
    creds = tools.run_flow(flow, store)
DRIVE = discovery.build('drive', 'v3', http=creds.authorize(Http()))

FILES = (
    ('hello.txt', None),
    ('hello.txt', 'application/vnd.google-apps.document'),
)

for filename, mimeType in FILES:
    metadata = {'name': filename}
    if mimeType:
        metadata['mimeType'] = mimeType
    res = DRIVE.files().create(body=metadata, media_body=filename).execute()
    if res:
        print('Uploaded "%s" (%s)' % (filename, res['mimeType']))

if res:
    MIMETYPE = 'application/pdf'
    data = DRIVE.files().export(fileId=res['id'], mimeType=MIMETYPE).execute()
    if data:
        fn = '%s.pdf' % os.path.splitext(filename)[0]
        with open(fn, 'wb') as fh:
            fh.write(data)
        print('Downloaded "%s" (%s)' % (fn, MIMETYPE))
)
Just as in the previous post(s), you can now customize this code for your own needs, for a mobile frontend, sysadmin script, or a server-side backend, perhaps accessing other Google APIs. Hope we accomplished our goal by pointing out some of the shortcomings that are in v2 and how they were improved in v3! All of the content in this and the previous post are spelled out visually in this video that I created for you.

Monday, December 14, 2015

Google Drive: Uploading & Downloading files with Python

UPDATE: Since this post was published, the Google Drive team released a newer version of their API. After reading this one, go to the next post to learn about migrating your app from v2 to v3 as well as link to my video which walks through the code samples in both posts.

Introduction

So far in this series of blogposts covering authorized Google APIs, we've used Python to access Google Drive, Gmail, and Google Calendar. Today, we're revisiting Google Drive with a small snippet that uploads plain text files to Drive, with & without conversion to a Google Apps format (Google Docs), then exports & downloads the converted one as PDF®.

Earlier posts demonstrated the structure and "how-to" use Google APIs in general, so more recent posts, including this one, focus on solutions and apps, and use of specific APIs. Once you review the earlier material, you're ready to start with authorization scopes then see how to use the API itself.

    Google Drive API Scopes

    Google Drive features numerous API scopes of authorization. As usual, we always recommend you use the most restrictive scope possible that allows your app to do its work. You'll request fewer permissions from your users (which makes them happier), and it also makes your app more secure, possibly preventing modifying, destroying, or corrupting data, or perhaps inadvertently going over quotas. Since we need to upload/create files in Google Drive, the minimum scope we need is:
    • 'https://www.googleapis.com/auth/drive' — Read/write access to Drive

    Using the Google Drive API

    Let's get going with our example today that uploads and downloads a simple plain text file to Drive. The file will be uploaded twice, once as-is, and the second time, converted to a Google Docs document. The last part of the script will request an export of the (uploaded) Google Doc as PDF and download that from Drive.

    Since we've fully covered the authorization boilerplate fully in earlier posts and videos, we're going to skip that here and jump right to the action, creating of a service endpoint to Drive. The API name is (of course) 'drive', and the current version of the API is 2, so use the string 'v2' in this call to the apiclient.discovey.build() function:

    DRIVE = build('drive', 'v2', http=creds.authorize(Http()))

    Let's also create a FILES array object (tuple, list, etc.) which holds 2-tuples of the files to upload. These pairs are made up of a filename and a flag indicating whether or not you wish the file to be converted to a Google Apps format:
    FILES = (
        ('hello.txt', False),
        ('hello.txt', True),
    )
    Since we're uploading a plain text file, a conversion to Apps format means Google Docs. (You can imagine that if it was a CSV file, the target format would be Google Sheets instead.) With the setup complete, let's move on to the code that performs the file uploads.

    We'll loop through FILES, cycling through each file-convert flag pair and call the files.insert() method to perform the upload. The four parameters needed are: 1) the conversion flag, 2) the file metadata, which is only the filename (see below), 3) the media_body, which is also the filename but has a different purpose — it specifies where the file content will come from, meaning the file will be opened and its data transferred to the API, and 4), a set of fields you want returned.
    for filename, convert in FILES:
        metadata = {'title': filename}
        res = DRIVE.files().insert(convert=convert, body=metadata,
                media_body=filename, fields='mimeType,exportLinks').execute()
        if res:
            print('Uploaded "%s" (%s)' % (filename, res['mimeType']))
    
    It's important to give the fields() parameter because if you don't, more than 30(!) are returned by default from the API. There's no need to waste all that network traffic if all you need are just a couple. In our case, we only want the mimeType, to confirm what the file was saved as, and exportLinks, which we'll explore in a moment. If files are uploaded successfully, the print() lets the user know, and then we move on to the final section of the script.

    Before we dig into the last bit of code, it's important to realize that the res variable still contains the result from the second upload, the one where the file is converted to Google Docs. This is important because this is where we need to extract the download link for the format you want (res['exportLinks'][MIMETYPE]). The way to download the file is to make an authorized HTTP GET call, passing in that link. In our case, it's the PDF version. If the download is successful, the data variable will have the payload to write to disk. If all's good, let the user know:
    if res:
        MIMETYPE = 'application/pdf'
        res, data = DRIVE._http.request(res['exportLinks'][MIMETYPE])
        if data:
            fn = '%s.pdf' % os.path.splitext(filename)[0]
            with open(fn, 'wb') as fh:
                fh.write(data)
            print('Downloaded "%s" (%s)' % (fn, MIMETYPE))
    
    Final note: this code sample is slightly different from previous posts in two big ways: 1) now that the Google APIs Client Library runs on Python 3, I'll try to produce only code samples for this blog that run unmodified under both 2.x and 3.x interpreters — the primary one-line difference being the import of the print() function, and 2) we're going to incorporate the use of the run_flow() function from oauth2client.tools and only fallback to the deprecated run() function if necessary — more info on this change available in this earlier post.

    If you run the script, grant the script access to your Google Drive (via the OAuth2 prompt that pops up in the browser), and then you should get output that looks like this:
    $ python drive_updown3.py # or python3
    Uploaded "hello.txt" (text/plain)
    Uploaded "hello.txt" (application/vnd.google-apps.document)
    Downloaded "hello.pdf" (application/pdf)
    

    Conclusion

    Below is the entire script for your convenience which runs on both Python 2 and Python 3 (unmodified!):
    #!/usr/bin/env python
    
    from __future__ import print_function
    import os
    
    from apiclient import discovery
    from httplib2 import Http
    from oauth2client import file, client, tools
    
    SCOPES = 'https://www.googleapis.com/auth/drive'
    store = file.Storage('storage.json')
    creds = store.get()
    if not creds or creds.invalid:
        flow = client.flow_from_clientsecrets('client_secret.json', SCOPES)
        creds = tools.run_flow(flow, store)
    DRIVE = discovery.build('drive', 'v2', http=creds.authorize(Http()))
    
    FILES = (
        ('hello.txt', False),
        ('hello.txt', True),
    )
    
    for filename, convert in FILES:
        metadata = {'title': filename}
        res = DRIVE.files().insert(convert=convert, body=metadata,
                media_body=filename, fields='mimeType,exportLinks').execute()
        if res:
            print('Uploaded "%s" (%s)' % (filename, res['mimeType']))
    
    if res:
        MIMETYPE = 'application/pdf'
        res, data = DRIVE._http.request(res['exportLinks'][MIMETYPE])
        if data:
            fn = '%s.pdf' % os.path.splitext(filename)[0]
            with open(fn, 'wb') as fh:
                fh.write(data)
            print('Downloaded "%s" (%s)' % (fn, MIMETYPE))
    
    You can now customize this code for your own needs, for a mobile frontend, sysadmin script, or a server-side backend, perhaps accessing other Google APIs. If you want to see another example of using the Drive API, check out this earlier post listing the files in Google Drive and its accompanying video as well as a similar example in the official docs or its equivalent in Java (server-side, Android), iOS (Objective-C, Swift), C#/.NET, PHP, Ruby, JavaScript (client-side, Node.js, Google Apps Script), or Go. That's it... hope you find these code samples useful in helping you get started with the Drive API!

    UPDATE: Since this post was published, the Google Drive team released a newer version of their API. Go to the next post to learn about migrating your app from v2 to v3 as well as link to my video which walks through the code samples in both posts.

    EXTRA CREDIT: Feel free to experiment and try something else to test your skills and challenge yourself as there's a lot more to Drive than just uploading and downloading files. Experiment with creating folders and manipulate files there, work with a folder of photos and organize them using the image metadata available to you, implement a search engine for your Drive files, etc. There are so many things you can do! 

    Tuesday, April 7, 2015

    Google APIs: migrating from tools.run() to tools.run_flow()

    Got AttributeError? As in: AttributeError: 'module' object has no attribute 'run'? Rename run() to run_flow(), and you'll be good-to-go. TL;DR: This mini-tutorial slash migration guide slash PSA (public service announcement) is aimed at Python developers using the Google APIs Client Library (to access Google APIs from their applications) currently calling oauth2client.tools.run() and likely getting an exception (see Jan 2016 update below), and need to oauth2client.tools.run_flow(), its replacement. 

    UPDATE (Aug 2016): The flags parameter in run_flow() function became optional in Feb 2016, so tweaked the blogpost to reflect that.

    UPDATE (Jun 2016): Revised the code and cleaned up the dialog so there are no longer any instances of using run() function, significantly shortening this post.

    UPDATE (Jan 2016): The tools.run() function itself was forcibly removed (without a fallback) in Aug 2015, so if you're using any release on or after that, any such calls from your code will throw an exception (AttributeError: 'module' object has no attribute 'run'). To fix this problem, continue reading.

    Prelude

    We're going to continue our look at accessing Google APIs from Python. In addition to the previous pair of posts (http://goo.gl/57Gufk and http://goo.gl/cdm3kZ), as part of my day job, I've been working on corresponding video content, some of which are tied specifically to posts on this blog.

    In this follow-up, we're going to specifically address the sidebar in the previous post, where we bookmarked an item for future discussion where the future is now: in the oauth2client package, tools.run() has been deprecated by tools.run_flow(). Note you need at least Python 2.7 or 3.3 to use the Google APIs Client Library. (If you didn't even know Python 3 was supported at all, then you need to see this post and this Quora Q&A.)

    Replacing tools.run() with tools.run_flow()

    Now let's convert the authorized access to Google APIs code from using tools.run() to tools.run_flow(). Here is the old snippet I'm talking about that needs upgrading:
    from apiclient import discovery
    from httplib2 import Http
    from oauth2client import file, client, tools
    
    SCOPES = # one or more scopes (str or iterable)
    store = file.Storage('storage.json')
    creds = store.get()
    if not creds or creds.invalid:
        flow = client.flow_from_clientsecrets('client_secret.json', SCOPES)
        creds = tools.run(flow, store)
    
    SERVICE = discovery.build(API, VERSION, http=creds.authorize(Http()))
    
    If you're using the latest Client Library (as of Feb 2016), all you need to do is change the tools.run() call to tools.run_flow(), as italicized below. Everything else stays exactly the same:
    from apiclient import discovery
    from httplib2 import Http
    from oauth2client import file, client, tools
    
    SCOPES = # one or more scopes (str or iterable)
    store = file.Storage('storage.json')
    creds = store.get()
    if not creds or creds.invalid:
        flow = client.flow_from_clientsecrets('client_secret.json', SCOPES)
        creds = tools.run_flow(flow, store)
    If you don't have the latest Client Library, then your update involves the extra steps of adding lines that import argparse and using it to get the flags argument needed by tools.run_flow() plus the actual change from tools.run(); all updates italicized below:
    import argparse
    
    from apiclient import discovery
    from httplib2 import Http
    from oauth2client import file, client, tools
    
    SCOPES = # one or more scopes (str or iterable)
    store = file.Storage('storage.json')
    creds = store.get()
    if not creds or creds.invalid:
        flags = argparse.ArgumentParser(parents=[tools.argparser]).parse_args()
        flow = client.flow_from_clientsecrets('client_id.json', SCOPES)
        creds = tools.run_flow(flow, store, flags)
    
    SERVICE = discovery.build(API, VERSION, http=creds.authorize(Http()))
    

    Command-line argument processing, or "Why argparse?"

    Python has had several modules in the Standard Library that allow developers to process command-line arguments. The original one was getopt which mirrored the getopt() function from C. In Python 2.3, optparse was introduced, featuring more powerful processing capabilities. However, it was deprecated in 2.7 in favor of a similar module, argparse. (To find out more about their similarities, differences and rationale behind developing argparse , see PEP 389 and this argparse docs page.) For the purposes of using Google APIs, you're all set if using Python 2.7 as it's included in the Standard Library. Otherwise Python 2.3-2.6 users can install it with: "pip install -U argparse". 

    Irregardless of whether you need argparse, once you migrate to either snippet with tools.run_flow(), your application should go back to working the way it had before.