How to use google cloud speech api in python

Question

I am exploring google cloud speech api in python.I am following this link. I also referred this stackoverflow link.But I got struck from setting the environment variables.

Things I have done:

1.Installed gcloud python module

2.Installed google-api-python-client module

3.Had Set up a Service account( obtained JSON File)

4.Obtained an API KEY

I got struck in exporting GOOGLE_APPLICATION_CREDENTIALS and GCLOUD_PROJECT environment variables.

My doubts are:

1.Should they be exported using google cloud sdk?If so,what role does google cloud sdk play here and when should we use this sdk?

2.Since I am not enclosing the API key explicitly in the code, does it mean that my authentication is automatically verified online?In such case what does my get_speech_service() function in the below code do?

Below is the code

import argparse
import base64
import json


import httplib2
from googleapiclient import discovery
from oauth2client.client import GoogleCredentials


if __name__ == '__main__':
   parser = argparse.ArgumentParser()
   parser.add_argument('speech_file',help='This is the path of the audio')
   args = parser.parse_args()
   print args.speech_file
   main(args.speech_file)

def main(speech_file):
    with open(speech_file,'rb') as speech:
         speech_content = base64.b64encode(speech.read())

    service = get_speech_service()
    service_request = service.speech().syncrecognize(
    body={
        'config':{
            'encoding':'LINEAR16',
            'sampleRate':16000,
            'languageCode':'en-US',
            },
        'audio':{
            'content':speech_content.decode('UTF-8')
            }
        })
    response = service_request.execute()
    print(json.dumps(response))
DISCOVERY_URL = ('https://speech.googleapis.com/$discovery/rest?/version=v1beta1')

def get_speech_service():
    credentials = GoogleCredentials.get_application_default().create_scoped(
    ['https://www.googleapis.com/auth/cloud-platform'])
    http = httplib2.Http()
    credentials.authorize(http)
    return    discovery.build('speech','v1beta1',http=http,discoveryServiceUrl=DISCOVERY_URL)

I googled many times and I obtained the mentioned stackoverflow link,which clarified some things.Since I am not clear with my above doubts I posted here.

Answer 1

Following steps worked for me. Hope it'll be of some use to you.

clone from github following repo:

git clone https://github.com/GoogleCloudPlatform/python-docs-samples.git

navigate to folder:

cd python-docs-samples/speech/cloud-client/

Install pip (am sure you already have this) and virtualenv . execute following commands:

$ virtualenv env
$ source env/bin/activate

Then install from requirements.txt

 pip install -r requirements.txt

define and export google credentials path (you are already doing this).

export GOOGLE_APPLICATION_CREDENTIALS=/path/to/service_account_file.json

start with the quick sample script:

python quickstart.py

You should be getting following output:

After this you can explore other scripts in the same folder and also try URI samples for long recognition.