List and download files in Google Drive. Utility class for a data dashboard.

gdrive.py

#Standard.
import io

#External (`pip install google-api-python-client google-auth-httplib2` should give you these.)
from oauth2client.service_account import ServiceAccountCredentials
from apiclient.discovery import build
from apiclient.http import MediaIoBaseDownload
import httplib2

class Tool():
    def __init__(self, credfile, 
                scopes=['https://spreadsheets.google.com/feeds', 
                        'https://www.googleapis.com/auth/drive']):
        """
        Constructor.
        
        Keyword Arguments:
        credfile - Path to the JSON credential file for your Service Account.
                Get this from the Google Developers Console: https://console.developers.google.com/
        scopes - A list of scopes required for your connection. The default
                should be fine.
        """

        credentials = ServiceAccountCredentials.from_json_keyfile_name(
                                credfile, scopes=scopes)
        self.service = build('drive', 'v3', credentials=credentials)

        #If this is in .service now, do I need it?
        self.http = credentials.authorize(httplib2.Http())

    def listFiles(self, filetype=None, folder=None, count=100, **kwargs):
        """
        List files in a Google drive.

        Keyword Arguments:
        type -- a MIME type. If you're looking for GSuite files, their
            types are listed at https://developers.google.com/drive/api/v3/mime-types
        folder -- the parent folder to search. Defaults you your entire drive.
        count -- Number of files to return. Can range from 1 to 1000. Overrides
            kwargs['pageSize'], if that's provided given.
            this function doesn't handle pagination.
        **kwargs -- additional parameters passed to the files.list API call. See
            https://developers.google.com/drive/api/v3/reference/files/list

        Also see https://developers.google.com/drive/api/v3/search-files

        Returns: a list of file descriptors. Exact contents may vary based on 
            kwargs['fields']'s value.
        """
        qs = []
        if filetype:
            qs.append("mimeType = '%s'" % filetype)
        if folder:
            qs.append("'%s' in parents" % folder)

        kwargs['pageSize'] = count

        response = self.service.files().list(q=' and '.join(qs),
                                            **kwargs).execute()
        
        return response['files']

    def downloadGSuite(self, file_id, ftype):
        """
        Download a G Suite document from Google Drive

        Keyword Arguments:
        file_id: Google's file id for the file. You could get it by querying the API 
            (maybe using listFiles()), or copy it from the address bar when looking at
            the file in your browser.
        ftype: The mime type of the export format you want. There's a list of 
            valid ones for each type of G Suite file at 
            https://developers.google.com/drive/api/v3/ref-export-formats

        Returns: an io.BytesIO object. This is a "file-like object" you can read from.
        """
        request = self.service.files().export_media(fileId=file_id,
                                                    mimeType=ftype)
        fh = io.BytesIO()
        downloader = MediaIoBaseDownload(fh, request)

        done = False
        while done is False:
            status, done = downloader.next_chunk()
        
        return fh