Progress Callback fixes

Author: Alexander Snorkin

pytorch_lightning/callbacks/progress.py

@@ -20,7 +20,10 @@
 
 """
 import importlib
+import io
+import os
 import sys
+from typing import Optional
 
 # check if ipywidgets is installed before importing tqdm.auto
 # to ensure it won't fail and a progress bar is displayed
@@ -150,11 +153,11 @@ def print(self, *args):
         """
         raise NotImplementedError
 
-    def print(self, *args):
+    def print(self, *args, **kwargs):
         """
         You should provide a way to print without breaking the progress bar.
         """
-        raise NotImplementedError
+        print(*args, **kwargs)
 
     def on_init_end(self, trainer):
         self._trainer = trainer
@@ -388,7 +391,14 @@ def on_test_end(self, trainer, pl_module):
         super().on_test_end(trainer, pl_module)
         self.test_progress_bar.close()
 
-    def print(self, *args, sep=' ', end='\n', file=None, nolock=False):
+    def print(
+        self,
+        *args,
+        sep: str = ' ',
+        end: str = os.linesep,
+        file: Optional[io.TextIOBase] = None,
+        nolock: bool = False
+    ):
         active_progress_bar = None
 
         if not self.main_progress_bar.disable: