Repository: Qiskit/qiskit
Issue category: Bug Report

Issue:
Doc string of `operation` in ParameterExpression._apply_operation
It says
```
operation: One of operator.{add,sub,mul,truediv}.
```
But the function is already called also with other operations, for example `pow` in `ParameterExpression.__pow__`.


Hints:
Good point, and while this is not user facing it would be nice to have the dev-facing docs correct. Would you like to open a small PR to fix it?

Patch:
diff --git a/qiskit/circuit/parameterexpression.py b/qiskit/circuit/parameterexpression.py
index fe786762c09..feaa0b772c7 100644
--- a/qiskit/circuit/parameterexpression.py
+++ b/qiskit/circuit/parameterexpression.py
@@ -340,7 +340,7 @@ def _apply_operation(
         either a constant or a second ParameterExpression.
 
         Args:
-            operation: One of operator.{add,sub,mul,truediv}.
+            operation: An operator, such as add, sub, mul, and truediv.
             other: The second argument to be used with self in operation.
             reflected: Optional - The default ordering is "self operator other".
                        If reflected is True, this is switched to "other operator self".


Test patch: