### Magma coercion equivalent in Sage?

I'm working on converting a code written in Magma to Sage. I have something like this in Magma:

```
Fp;=FiniteField(p);
if (p mod 4) eq 3 then
q:=1;
else
q:=3;
while IsSquare(-Fp!q) do
q:=q+4;
end while;
end if;
```

Now there is the `!`

operator used, which is called coercion in Magma. Is there an equivalent operator in Sage? I mean how would one conver the `IsSquare(-Fp!q)`

part valid Sage?