Undated changelog and added a test case

doc/releases/changelog-dev.md

@@ -127,6 +127,9 @@
 
 <h3>Bug fixes 🐛</h3>
 
+* `hamiltonian comaparison` now also `rounds off the float to 15digit` to remove float point errors. Have just added a line of rounded float comaprison.
+[(#4567)](https://github.com/PennyLaneAI/pennylane/issues/4567)
+
 * `convert_to_numpy_parameters` now uses `qml.ops.functions.bind_new_parameters`. This reinitializes the operation and
   makes sure everything references the new numpy parameters.
 
@@ -141,4 +144,4 @@ Lillian M. A. Frederiksen,
 Romain Moyard,
 Mudit Pandey,
 Matthew Silverman
-
+Yash Prabhat

pennylane/ops/qubit/hamiltonian.py

@@ -616,6 +616,9 @@ def compare(self, other):
         if isinstance(other, Hamiltonian):
             self.simplify()
             other.simplify()
+            if self._obs_data() == other._obs_data() : # pylint: disable=protected-access
+                return True
+            #for removing float point error
             return ((round(list(self._obs_data())[0][0],15),list(self._obs_data())[0][1]) == (
                 (round(list(other._obs_data())[0][0],15), list(other._obs_data())[0][1])))  # pylint: disable=protected-access
 

tests/test_hamiltonian_compare.py

@@ -0,0 +1,7 @@
+#to test if hamiltonian comapre function has float point error
+import pennylane as qml
+
+def test_hamiltonian_compare():
+    H2 = qml.Hamiltonian([0.3, 0.3], [qml.PauliZ(0), qml.PauliZ(0)])
+    H1 = qml.Hamiltonian([0.1, 0.2, 0.3], [qml.PauliZ(0), qml.PauliZ(0), qml.PauliZ(0)])
+    assert (H1.compare(H2))