Django initialize the database has encountered a problem (python manage.py migrate)

问题：django.db.utils.InternalError: (1049, "Unknown database 'main'")

 Create database to perform on the main Django configuration database to create main database

问题：AttributeError: 'str' object has no attribute 'decode'

Because django of python2.x and 3.x support is not the same, in python3.x the need to comment out the following code (if two sentences)