Are lambdas allowed in dictionary comprehensions?

Question

I have the following:

>>> {c: (lambda: c) for c in ["A","B"]}["A"]()
'B'

when I expect the result to be 'A'.

Note that

>>> {c: c for c in ["A","B"]}["A"]
'A'

Are lambdas not allowed in dictionary comprehensions or have I screwed up the syntax?

Answer 1

There's one object created by the lambda, and the value that it captures is modified during each element of the comprehension

It is the same as if you did

class Lambda:
    def set(self, value):
        self.value = value;
        return self
    def __call__(self):
        return value

lam = Lambda()
{c: lam.set(c) for c in ["A","B"]}["A"]()

Each entry in the dictionary has the same value, lam, that returns the last set value.