aawgit

from main_module import main_func


def test_main_func_mocked(monkeypatch):
    monkeypatch.setattr('main_module.service_func', lambda : 'mocked result')
    assert main_func() == 'mocked result'

aawgit

from main_module import main_func, main_func_2

def test_main_func(monkeypatch):
    monkeypatch.setattr('sub_module.service_func', lambda : 'mocked result')
    assert main_func() == 'mocked result'

aawgit

import logging


def service_func():
    logging.info('From sub modules function')
    return 'sub mod result'

aawgit

from sub_module import service_func
import logging


def main_func():
    logging.info('Calling sub modules function')
    result = service_func()
    return result

aawgit

from airflow import DAG
from airflow.operators.python_operator import PythonOperator

def error_function():
    raise Exception('Something wrong')
   
t2 = PythonOperator(
    task_id='failing_task',
    python_callable=error_function,
    email_on_failure=True,

aawgit

from airflow import DAG
from airflow.operators.email_operator import EmailOperator

t1 = EmailOperator(
    task_id="send_mail", 
    to='receiver@mail.com',
    subject='Test mail',
    html_content='<p> You have got mail! <p>',
    dag=dag)

aawgit

from flask import Flask
app = Flask(__name__)

@app.route('/')
def hello_world():
    return 'Hello, World!'