In this section, we are going to create the configuration file for our application; the configuration file will be in YAML format. If you would like to know more about YAML, you can check the site http://yaml.org/, where you will find examples, the specification, and also a list of libraries in different programming languages that can be used to manipulate YAML files.
For our application, we are going to use PyYAML, which will allow us to read and write YAML files in a very simple manner. Our configuration file is quite simple so we will not need to use any advanced features of the library, we just want to read the content and write, and the data that we are going to add is quite flat; we will not have any nested objects or lists of any kind.
Let's get the information that we obtained from Twitter when we created our app and add it to the configuration...