None vs ~

[nicholebarry]

Config file requires ~ instead of None if you want to not set a variable. It would be nice for it to be pythonic as well, i.e. take None and understand it as None

[SkyWa7ch3r]

You have a couple of options here:

1. Easiest, though more likely to potentially encounter weird behavior, create a custom type that checks for the None exactly, and it does specify as None
2. The better method, but slightly more complex, extend the YAML parser to recognize None as null (i.e. make a class PyFHDYAMLParser that inherits from YAMLConfigFileParser), this is done with the use of add_implicit_resolver inside the __init__ of the class, where you'd set regex to recognize None.
3. Alternatively instead of ~ you can also use null in YAML, while it's not None it may be close enough for your needs and should require no code changes.

Both 1 & 2 will end up with the syntax you desire in YAML:

example-arg: None

If you decide to stick with the default YAML parser then you can do

example-arg: ~
# or
example-arg: null

[bhazelton]

I can live with ~ or null but we need much more explicit docs explaining that ~ translates to None in python. After I realized it I could find mentions of it in the tutorial but I did not notice them until after I had tried to set it to None and many other things.

[bhazelton]

I tried to improve this documentation in #71