Relax logger check for Windows (#1615)

* Relax logger check for Windows

* Update tests

docs/misc/changelog.rst

@@ -4,7 +4,7 @@ Changelog
 ==========
 
 
-Release 2.1.0a1 (WIP)
+Release 2.1.0a2 (WIP)
 --------------------------
 
 Breaking Changes:
@@ -25,6 +25,7 @@ New Features:
 
 Bug Fixes:
 ^^^^^^^^^^
+- Relaxed check in logger, that was causing issue on Windows with colorama
 
 Deprecations:
 ^^^^^^^^^^^^^

stable_baselines3/common/logger.py

@@ -164,8 +164,10 @@ def __init__(self, filename_or_file: Union[str, TextIO], max_length: int = 36):
         if isinstance(filename_or_file, str):
             self.file = open(filename_or_file, "w")
             self.own_file = True
-        elif isinstance(filename_or_file, TextIOBase):
-            self.file = filename_or_file
+        elif isinstance(filename_or_file, TextIOBase) or hasattr(filename_or_file, "write"):
+            # Note: in theory `TextIOBase` check should be sufficient,
+            # in practice, libraries don't always inherit from it, see GH#1598
+            self.file = filename_or_file  # type: ignore[assignment]
             self.own_file = False
         else:
             raise ValueError(f"Expected file or str, got {filename_or_file}")

stable_baselines3/version.txt

@@ -1 +1 @@
-2.1.0a1
+2.1.0a2

tests/test_logger.py

@@ -437,8 +437,9 @@ def test_ep_buffers_stats_window_size(algo, stats_window_size):
     assert model.ep_success_buffer.maxlen == stats_window_size
 
 
-def test_human_output_format_custom_test_io():
-    class DummyTextIO(TextIOBase):
+@pytest.mark.parametrize("base_class", [object, TextIOBase])
+def test_human_output_format_custom_test_io(base_class):
+    class DummyTextIO(base_class):
         def __init__(self) -> None:
             super().__init__()
             self.lines = [[]]