Add is_kaggle() function (#6285)

* Add `is_kaggle()` function

Return True if environment is Kaggle Notebook.

* Remove root loggers only if is_kaggle() == True

* Update general.py

utils/general.py

@@ -44,10 +44,21 @@ cv2.setNumThreads(0)  # prevent OpenCV from multithreading (incompatible with Py
 os.environ['NUMEXPR_MAX_THREADS'] = str(NUM_THREADS)  # NumExpr max threads
 
 
+def is_kaggle():
+    # Is environment a Kaggle Notebook?
+    try:
+        assert os.environ.get('PWD') == '/kaggle/working'
+        assert os.environ.get('KAGGLE_URL_BASE') == 'https://www.kaggle.com'
+        return True
+    except AssertionError:
+        return False
+
+
 def set_logging(name=None, verbose=True):
     # Sets level and returns logger
-    for h in logging.root.handlers:
-        logging.root.removeHandler(h)  # remove all handlers associated with the root logger object
+    if is_kaggle():
+        for h in logging.root.handlers:
+            logging.root.removeHandler(h)  # remove all handlers associated with the root logger object
     rank = int(os.getenv('RANK', -1))  # rank in world for Multi-GPU trainings
     logging.basicConfig(format="%(message)s", level=logging.INFO if (verbose and rank in (-1, 0)) else logging.WARNING)
     return logging.getLogger(name)