More Pythonic boolean comparisons

ch03/bb84.py

@@ -74,8 +74,8 @@ def simulate_bb84(n_bits: int) -> list:
         ((your_message, your_basis), (eve_result, eve_basis)) = \
             send_single_bit_with_bb84(your_device, eve_device)
 
-        if your_basis == eve_basis:
-            assert your_message == eve_result
+        if your_basis is eve_basis:
+            assert your_message is eve_result
             key.append(your_message)
 
     print(f"Took {n_rounds} rounds to generate a {n_bits}-bit key.")
@@ -114,4 +114,4 @@ def apply_one_time_pad(message: List[bool], key: List[bool]) -> List[bool]:
 
     decrypted_message = apply_one_time_pad(encrypted_message, key)
     print(f"Eve decrypted to get:             {convert_to_hex(decrypted_message)}.")
-
+    

ch03/qkd.py

@@ -12,7 +12,6 @@
 ##
 
 from interface import QuantumDevice, Qubit
-from simulator import SingleQubitSimulator
 
 def prepare_classical_message(bit: bool, q: Qubit) -> None:
     if bit:
@@ -26,7 +25,7 @@ def send_classical_bit(device: QuantumDevice, bit: bool) -> None:
         prepare_classical_message(bit, q)
         result = eve_measure(q)
         q.reset()
-    assert result == bit
+    assert result is bit
 
 
 def qrng(device: QuantumDevice) -> bool:
@@ -47,10 +46,10 @@ def send_classical_bit_plusminus(device: QuantumDevice, bit: bool) -> None:
     with device.using_qubit() as q:
         prepare_classical_message_plusminus(bit, q)
         result = eve_measure_plusminus(q)
-        assert result == bit
+        assert result is bit
 
 def send_classical_bit_wrong_basis(device: QuantumDevice, bit: bool) -> None:
     with device.using_qubit() as q:
         prepare_classical_message(bit, q)
         result = eve_measure_plusminus(q)
-        assert result == bit, "Two parties do not have the same bit value"
+        assert result is bit, "Two parties do not have the same bit value"

ch04/chsh.py

@@ -20,7 +20,6 @@
 from typing import Tuple, Callable
 import numpy as np
 
-from interface import QuantumDevice, Qubit
 from simulator import Simulator
 
 Strategy = Tuple[Callable[[int], int], Callable[[int], int]]
@@ -31,8 +30,8 @@ def random_bit() -> int:
 def referee(strategy: Callable[[], Strategy]) -> bool:
     you, eve = strategy()
     your_input, eve_input = random_bit(), random_bit()
-    parity = 0 if you(your_input) == eve(eve_input) else 1
-    return parity == (your_input and eve_input)
+    parity = 0 if you(your_input) is eve(eve_input) else 1
+    return bool(parity) is (bool(your_input) and bool(eve_input))
 
 def est_win_probability(strategy: Callable[[], Strategy],
                         n_games: int = 1000) -> float:

ch05/chsh.py

@@ -16,7 +16,6 @@
 from typing import Tuple, Callable
 import numpy as np
 
-from interface import QuantumDevice, Qubit
 from simulator import Simulator
 
 Strategy = Tuple[Callable[[int], int], Callable[[int], int]]
@@ -27,8 +26,8 @@ def random_bit() -> int:
 def referee(strategy: Callable[[], Strategy]) -> bool:
     you, eve = strategy()
     your_input, eve_input = random_bit(), random_bit()
-    parity = 0 if you(your_input) == eve(eve_input) else 1
-    return parity == (your_input and eve_input)
+    parity = 0 if you(your_input) is eve(eve_input) else 1
+    return bool(parity) == (bool(your_input) and bool(eve_input))
 
 def est_win_probability(strategy: Callable[[], Strategy],
                         n_games: int = 1000) -> float: