I am working with an ini file where the default section is named 'default' and not 'DEFAULT'. Pythons `ConfigParser` seams to handle these sections ok with no problem. However, for whatever reason, they dont allow you to add a 'default' section or write to it. 
In the code, they have hardcoded that you can not create a section of any case-insensitive version of 'DEFAULT'. 

So if I can not add the section 'default' how do I write to it? The spec says you write to 'DEFAULT' since the section always exists. However, how to I write to 'default'?

I want to stay consistent with the way the file is already written, so I want the default section to be written in lowercase and not all uppercase. 

If the file doesnt exist yet, I want to add the [default] section. Writing to section 'default' gives me a `ValueError: Invalid section name: default`

(note: writing to default works fine when I use an already correctly formatted file)

Also, I am willing to listen to suggestions for other configuration libraries I can use. But they must not be 3rd party (I shouldn't need to pip install them)