Disconnect stdout/stderr logger on exit

trains/backend_interface/logger.py

@@ -77,17 +77,17 @@ class StdStreamPatch(object):
                 StdStreamPatch._stderr_proxy.connect(logger)
 
     @staticmethod
-    def remove_std_logger():
+    def remove_std_logger(logger=None):
         if isinstance(sys.stdout, PrintPatchLogger):
             # noinspection PyBroadException
             try:
-                sys.stdout.connect(None)
+                sys.stdout.disconnect(logger)
             except Exception:
                 pass
         if isinstance(sys.stderr, PrintPatchLogger):
             # noinspection PyBroadException
             try:
-                sys.stderr.connect(None)
+                sys.stderr.disconnect(logger)
             except Exception:
                 pass
 
@@ -172,6 +172,11 @@ class PrintPatchLogger(object):
         self._cur_line = ''
         self._log = logger
 
+    def disconnect(self, logger=None):
+        # disconnect the logger only if it was registered
+        if not logger or self._log == logger:
+            self.connect(None)
+
     def __getattr__(self, attr):
         if attr in ['_log', '_terminal', '_log_level', '_cur_line']:
             return self.__dict__.get(attr)

trains/logger.py

@@ -735,6 +735,9 @@ class Logger(object):
             self._task_handler.flush()
 
     def _close_stdout_handler(self, wait=True):
+        # detach the sys stdout/stderr
+        StdStreamPatch.remove_std_logger(self)
+
         if self._task_handler and DevWorker.report_stdout:
             t = self._task_handler
             self._task_handler = None