Documenting with Sphinx python methods that do have default parameters with sentinel objects?

Question

If you want to be able to allow people to call some methods using None you have to do use a sentinel object when you define the method.

 _senti         


        

Answer 1

I don't think it is possible to persuade Sphinx to be more "friendly" as long as you have a sentinel that creates an object outside the function. Sphinx' autodoc extension imports the module, which means that module-level code is executed.

Are you sure you can't use something like this?

def foo(param1=None):
    if param1 == None:
        param1 = whatever you want...
    else:
         ... 

Answer 2

This can be handled by manually specifying function signature in autodoc directive, e.g.:

.. automodule:: pymorphy.contrib.tokenizers

    .. autofunction:: extract_tokens(foo, bar)

    .. autofunction:: extract_words

Answer 3

The <object object at 0x108c1a520> part of generated method signature can be changed by overriding the __repr__ method of the sentinel object.

_sentinel = type('_sentinel', (object,),
                 {'__repr__': lambda self: '_sentinel'})()

It will be rendered by Sphinx as something like this:

mymodule.foo(param1=_sentinel)