explicit credentials in dialogflow python library

Question

someone have build a python project with the new dialogflow library from python language, I already make it work with implicit credentials but now I need to make it work with explicit credentials.

This is the error:

google.auth.exceptions.DefaultCredentialsError: Could not automatically          determine credentials. 
Please set GOOGLE_APPLICATION_CREDENTIALS or
explicitly create credential and re-run the application. For more
information, please see
https://developers.google.com/accounts/docs/application-default-credentials.

The url only explain explicit credentials.

This is the code that am using:

import dialogflow

def create_intent(project_id, display_name, training_phrases_parts,
              message_texts):

"""Create an intent of the given intent type."""
intents_client = dialogflow.IntentsClient()

parent = intents_client.project_agent_path(project_id)
training_phrases = []
for training_phrases_part in training_phrases_parts:
    part = dialogflow.types.Intent.TrainingPhrase.Part(
        text=training_phrases_part)
    # Here we create a new training phrase for each provided part.
    training_phrase = dialogflow.types.Intent.TrainingPhrase(parts=[part])
    training_phrases.append(training_phrase)

text = dialogflow.types.Intent.Message.Text(text=message_texts)
message = dialogflow.types.Intent.Message(text=text)

intent = dialogflow.types.Intent(
    display_name=display_name,
    training_phrases=training_phrases,
    messages=[message])

response = intents_client.create_intent(parent, intent)

print('Intent created: {}'.format(response))

Answer 1

At the end was the same that google.cloud library from python

import os
os.environ["GOOGLE_APPLICATION_CREDENTIALS"]="./path_to.json"