How to run python script with the same port - python-3.x

Question

Right now I am setting up oauth2 from Gmail to send mail from my python script.
I am using a quick start code from Google to verify the authorize code but I am facing a situation where the port always changes when I am running the python script.
from __future__ import print_function
import pickle
import os.path
from googleapiclient.discovery import build
from google_auth_oauthlib.flow import InstalledAppFlow
from google.auth.transport.requests import Request
# If modifying these scopes, delete the file token.pickle.
SCOPES = ['https://www.googleapis.com/auth/gmail.readonly']
def main():
"""Shows basic usage of the Gmail API.
Lists the user's Gmail labels.
"""
creds = None
# The file token.pickle stores the user's access and refresh tokens, and is
# created automatically when the authorization flow completes for the first
# time.
if os.path.exists('token.pickle'):
with open('token.pickle', 'rb') as token:
creds = pickle.load(token)
# If there are no (valid) credentials available, let the user log in.
if not creds or not creds.valid:
if creds and creds.expired and creds.refresh_token:
creds.refresh(Request())
else:
flow = InstalledAppFlow.from_client_secrets_file(
'../credentials.json', SCOPES)
creds = flow.run_local_server(port=0)
# Save the credentials for the next run
with open('token.pickle', 'wb') as token:
pickle.dump(creds, token)
service = build('gmail', 'v1', credentials=creds)
# Call the Gmail API
results = service.users().labels().list(userId='me').execute()
labels = results.get('labels', [])
if not labels:
print('No labels found.')
else:
print('Labels:')
for label in labels:
print(label['name'])
if __name__ == '__main__':
main()
My problem with this code is that whenever I run the script, it always changes the port and I cannot set the redirected URI in google console.
My question is that how can I set the running port on python script?

Answer 1

For example, how about the following modification?
From:
creds = flow.run_local_server(port=0)
To:
creds = flow.run_local_server()
In this case, the port 8080 is used every time.
or
creds = flow.run_local_server(port=8000)
In this case, the port 8000 is used every time.
Reference:
run_local_server