Update after failed tests

henklaak · henklaak · commit 8101b31992de · 2023-02-25T12:39:09.000+01:00
diff --git a/control/tests/xferfcn_test.py b/control/tests/xferfcn_test.py
@@ -966,7 +966,7 @@ def test_printing_mimo(self):
          ])
     def test_printing_zpk(self, zeros, poles, gain, output):
         """Test _tf_polynomial_to_string for constant systems"""
-        G = zpk(zeros, poles, gain)
+        G = zpk(zeros, poles, gain, display_format='zpk')
         res = str(G)
         assert res == output
 
diff --git a/control/xferfcn.py b/control/xferfcn.py
@@ -486,7 +486,7 @@ def __str__(self, var=None):
                 outstr += "\n" + numstr + "\n" + dashes + "\n" + denstr + "\n"
 
         # If this is a strict discrete time system, print the sampling time
-        if self.isdtime(strict=True):
+        if type(self.dt) != bool and self.isdtime(strict=True):
             outstr += "\ndt = " + str(self.dt) + "\n"
 
         return outstr
