[Python] Easiest way to copy all fields from one dataclass instance to another?

Let's assume you have defined a Python dataclass:

@dataclass
class Marker:
a: float
b: float = 1.0


What's the easiest way to copy the values from an instance marker_a to another instance marker_b?

Here's an example of what I try to achieve:

marker_a = Marker(1.0, 2.0)
marker_b = Marker(11.0, 12.0)
# now some magic happens which you hopefully can fill in
print(marker_b)
# result: Marker(a=1.0, b=2.0)


As a boundary condition, I do not want to create and assign a new instance to marker_b.

OK, I could loop through all defined fields and copy the values one by one, but there has to be a simpler way, I guess.

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