Fix the timeout flag in the python wrapper

The timeout was incorrectly expressed as an integer in terms of
milliseconds. It now correctly works as a float in terms of
seconds.

Author: arcondello

python/dwave_qbsolv/qbsolv_binding.pyx

@@ -99,8 +99,8 @@ def run_qbsolv(Q, num_repeats=50, seed=17932241798878,  verbosity=-1,
     else:
         raise ValueError('unknown algorithm given')
 
-    if not isinstance(timeout, int) or timeout <= 0:
-        raise ValueError("'timeout' must be a positive integer")
+    if timeout <= 0:
+        raise ValueError("'timeout' must be positive")
     global Time_
     Time_ = timeout # the maximum runtime of the algorithm in seconds before timeout (2592000 = a month's worth of seconds)
 

tests/test_dwave_qbsolv.py

@@ -1,5 +1,5 @@
 import unittest
-
+import time
 import itertools
 
 import dwave_qbsolv as qbs
@@ -69,3 +69,18 @@ def test_energy_calculation(self):
 
         for sample, energy in response.data(['sample', 'energy']):
             self.assertAlmostEqual(dimod.ising_energy(sample, h, J), energy)
+
+    # these tests are hard to automate for CI because different systems have different
+    # speeds
+    # def test_timeout_parameter(self):
+    #     # set up a problem we hope will take a long time
+    #     Q = {edge: random.uniform(-1, 1) for edge in itertools.combinations_with_replacement(range(500), 2)}
+
+    #     timeout = 1 # in seconds
+
+    #     t = time.time()
+
+    #     response = qbs.QBSolv().sample_qubo(Q, timeout=timeout)  # seconds to millisconds
+        
+    #     # let's be generous and give it 3x the timeout
+    #     self.assertLessEqual(time.time() - t, 3*timeout)