Change Cosmology name when parameters change in clone

[nstarman]

Description

Cloning a cosmology with changed parameters now appends "(modified)" to the
new instance's name, unless a name is explicitly passed to clone.

The problem can be seen when cloning a built-in cosmology and changing a parameter — eg Planck18.clone(H0=10). This should NOT have the same name because it is not the same thing.

[hamogu]

I'm curious why you use "setdefault" here since the return value if the function is not used.

Suggested change

	kwargs.setdefault("name", (self.name + " (modified)"
	kwargs['name'] = None if self.name is None else self.name + " (modified)"

[hamogu]

Note that this suggestion can't be applied directly, since the line below will also have to be removed.

[nstarman]

I used setdefault because it only sets the value if one is not already present. The suggested code doesn't quite work because it doesn't check if kwargs already has "name", in which case it should not be changed. An alternative one-liner is
kwargs["name"] = kwargs.get("name", self.name + " (modified)" if self.name is not None else None).

[nstarman]

It was mostly just a lazy way of skipping an if-block to make getting that 100% codecov easier. This doesn't need multiple test cases, unlike the equivalent code.

if "name" not in kwargs:
    kwargs['name'] = None if self.name is None else self.name + " (modified)"

[hamogu]

Great, thank you for the explanation. I did not know about "setdefault" before, I will definitely use that more often in the future myself!

[nstarman]

Thanks @hamogu for the review!