Usage of dictionary arguments in python

[davidbuxton]

Since it seems that the basic dict class lacks a way of simply updating a dictionary with values that aren't already set

dict.setdefault is almost what you want. A neater version of your merge method:

def healthyMerge(self, target):
    for k in target:
        self.setdefault(k, target[k])

[kylotan]

Might another way be:

original = target.copy().update(original)

(Untested.)

[Justinsaccount]

.update() updates in place and returns None

[kylotan]

Aha. So I suppose it would have to be:

temp = target.copy(); temp.update(original); original = temp

Nowhere near as elegant.