Make sure pexpect uses same version of Python to spawn persistent history example

Author: tleonhardt

examples/persistent_history.py

@@ -10,14 +10,24 @@
 
 class Cmd2PersistentHistory(cmd2.Cmd):
     """Basic example of how to enable persistent readline history within your cmd2 app."""
-    def __init__(self):
-        """"""
-        cmd2.Cmd.__init__(self, persistent_history_file='~/.persistent_history.cmd2', persistent_history_length=500)
+    def __init__(self, hist_file):
+        """Configure the app to load persistent readline history from a file.
+
+        :param hist_file: file to load readline history from at start and write it to at end
+        """
+        cmd2.Cmd.__init__(self, persistent_history_file=hist_file, persistent_history_length=500)
+        self.allow_cli_args = False
         self.prompt = 'ph> '
 
     # ... your class code here ...
 
 
 if __name__ == '__main__':
-    app = Cmd2PersistentHistory()
+    import sys
+
+    history_file = '~/.persistent_history.cmd2'
+    if len(sys.argv) > 1:
+        history_file = sys.argv[1]
+
+    app = Cmd2PersistentHistory(hist_file=history_file)
     app.cmdloop()

tests/test_cmd2.py

@@ -1532,8 +1532,14 @@ def test_persistent_history(request):
     test_dir = os.path.dirname(request.module.__file__)
     persistent_app = os.path.join(test_dir, '..', 'examples', 'persistent_history.py')
 
+    python = 'python3'
+    if six.PY2:
+        python = 'python2'
+
+    command = '{} {}'.format(python, persistent_app)
+
     # Start an instance of the persistent history example and send it a few commands
-    child = pexpect.spawn(persistent_app)
+    child = pexpect.spawn(command)
     prompt = 'ph> '
     child.expect(prompt)
     child.sendline('help')
@@ -1545,10 +1551,9 @@ def test_persistent_history(request):
 
     # Start a 2nd instance of the persistent history example and send it an up arrow to verify persistent history
     up_arrow = '\x1b[A'
-    child2 = pexpect.spawn(persistent_app)
+    child2 = pexpect.spawn(command)
     child2.expect(prompt)
     child2.send(up_arrow)
     child2.expect('quit')
     assert child2.after == b'quit'
-
-
+    child2.close()