Recursively traverse the directory tree of a Google Drive folder as variation of os.walk()

walk_gdrive.py

# walk_gdrive.py - os.walk variation with Google Drive API

import os

from apiclient.discovery import build  # pip install google-api-python-client

FOLDER = 'application/vnd.google-apps.folder'

def get_credentials(scopes, secrets='~/client_secrets.json', storage='~/storage.json'):
    from oauth2client import file, client, tools
    store = file.Storage(os.path.expanduser(storage))
    creds = store.get()
    if creds is None or creds.invalid:
        flow = client.flow_from_clientsecrets(os.path.expanduser(secrets), scopes)
        flags = tools.argparser.parse_args([])
        creds = tools.run_flow(flow, store, flags)
    return creds

creds = get_credentials(scopes=['https://www.googleapis.com/auth/drive.metadata.readonly'])
service = build('drive', version='v3', credentials=creds)

def iterfiles(name=None, is_folder=None, parent=None, order_by='folder,name,createdTime'):
    q = []
    if name is not None:
        q.append("name = '%s'" % name.replace("'", "\\'"))
    if is_folder is not None:
        q.append("mimeType %s '%s'" % ('=' if is_folder else '!=', FOLDER))
    if parent is not None:
        q.append("'%s' in parents" % parent.replace("'", "\\'"))
    params = {'pageToken': None, 'orderBy': order_by}
    if q:
        params['q'] = ' and '.join(q)
    while True:
        response = service.files().list(**params).execute()
        for f in response['files']:
            yield f
        try:
            params['pageToken'] = response['nextPageToken']
        except KeyError:
            return

def walk(top='root', by_name=False):
    if by_name:
        top, = iterfiles(name=top, is_folder=True)
    else:
        top = service.files().get(fileId=top).execute()
        if top['mimeType'] != FOLDER:
            raise ValueError('not a folder: %r' % top)
    stack = [((top['name'],), top)]
    while stack:
        path, top = stack.pop()
        dirs, files = is_file = [], []
        for f in iterfiles(parent=top['id']):
            is_file[f['mimeType'] != FOLDER].append(f)
        yield path, top, dirs, files
        if dirs:
            stack.extend((path + (d['name'],), d) for d in reversed(dirs))

for kwargs in [{'top': 'spam', 'by_name': True}, {}]:
    for path, root, dirs, files in walk(**kwargs):
        print('%s\t%d %d' % ('/'.join(path), len(dirs), len(files)))