_mysql_exceptions.OperationalError: (1045, "Access denied for user 'root'@'localhost' (using password: NO)") code example

Example 1: ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)

# Stop Your Server First
sudo service mysql stop

# Make MySQL service directory.
sudo mkdir /var/run/mysqld

# Give MySQL permission to work with the created directory
sudo chown mysql: /var/run/mysqld

# Start MySQL, without permission and network checking
sudo mysqld_safe --skip-grant-tables --skip-networking &

# Log in to your server without any password.
mysql -u root mysql


# Update the password for the root user:
UPDATE mysql.user SET authentication_string=PASSWORD('YourNewPasswordBuddy'), plugin='mysql_native_password' WHERE User='root' AND Host='localhost';

#if you omit (AND Host='localhost') section, it updates the root pass regardless of its host

FLUSH PRIVILEGES;
EXIT;

#kill mysqld_safe process
sudo service mysql restart

#Now you can use your new password to login to your Server
mysql -u root -p

#take note for remote access you should create a remote user and then grant all privileges to that remote user

Example 2: django.db.utils.OperationalError: (1045, "Access denied for user 'root'@'localhost' (using password: YES)")

You need to make changes in project settings.py. 
Provide USER and PASSWORD for your database
If your database isn't mysql change ENGINE

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.mysql',
        'NAME': 'myproject',
        'USER': 'root',
        'PASSWORD': 'rootpassword',
        'HOST': 'localhost',
        'PORT': '',
    }
}