Here’s how I remember: dumps() takes no file-like argument, thus for dump() and dumps() to be consistent, the object to dump() must come first.

That argument would make as much sense if you replaced first by last.

Optional arguments are almost always trailing arguments:

    dumps(obj)
    dump(obj, fp)

Might be implemented (in a Pythonic way) by the same function:

    fn(obj, fp=None):
        ...

Another way to think about it is that you're dumping from obj to fp. The thing I always get backwards is C's memcpy(dst, src, len) which I've always thought has its first two arguments in the wrong order.

Agreed. I did that as a simple way to prevent abuse. I'll have bring back special characters.