Logging doc (#6852)

* Add logging doc

* Foamtting

* Update docs/source/main_classes/logging.rst

* Update src/transformers/utils/logging.py

Co-authored-by: Lysandre Debut <lysandre@huggingface.co>

src/transformers/utils/logging.py

@@ -73,8 +73,10 @@ def _reset_library_root_logger() -> None:
 
 
 def get_logger(name: Optional[str] = None) -> logging.Logger:
-    """Return a logger with the specified name.
-    This function is not supposed to be directly accessed by library users.
+    """
+    Return a logger with the specified name.
+
+    This function is not supposed to be directly accessed unless you are writing a custom transformers module.
     """
 
     if name is None:
@@ -85,16 +87,21 @@ def get_logger(name: Optional[str] = None) -> logging.Logger:
 
 
 def get_verbosity() -> int:
-    """Return the current level for the HuggingFace Transformers's root logger.
+    """
+    Return the current level for the 🤗 Transformers's root logger as an int.
+
     Returns:
-        Logging level, e.g., ``transformers.logging.DEBUG`` and ``transformers.logging.INFO``.
+        :obj:`int`: The logging level.
+
     .. note::
-        HuggingFace Transformers has following logging levels:
-        - ``transformers.logging.CRITICAL``, ``transformers.logging.FATAL``
-        - ``transformers.logging.ERROR``
-        - ``transformers.logging.WARNING``, ``transformers.logging.WARN``
-        - ``transformers.logging.INFO``
-        - ``transformers.logging.DEBUG``
+
+        🤗 Transformers has following logging levels:
+
+        - 50: ``transformers.logging.CRITICAL`` or ``transformers.logging.FATAL``
+        - 40: ``transformers.logging.ERROR``
+        - 30: ``transformers.logging.WARNING`` or ``transformers.logging.WARN``
+        - 20: ``transformers.logging.INFO``
+        - 10: ``transformers.logging.DEBUG``
     """
 
     _configure_library_root_logger()
@@ -102,10 +109,18 @@ def get_verbosity() -> int:
 
 
 def set_verbosity(verbosity: int) -> None:
-    """Set the level for the HuggingFace Transformers's root logger.
+    """
+    Set the vebosity level for the 🤗 Transformers's root logger.
+
     Args:
-        verbosity:
-            Logging level, e.g., ``transformers.logging.DEBUG`` and ``transformers.logging.INFO``.
+        verbosity (:obj:`int`):
+            Logging level, e.g., one of:
+
+            - ``transformers.logging.CRITICAL`` or ``transformers.logging.FATAL``
+            - ``transformers.logging.ERROR``
+            - ``transformers.logging.WARNING`` or ``transformers.logging.WARN``
+            - ``transformers.logging.INFO``
+            - ``transformers.logging.DEBUG``
     """
 
     _configure_library_root_logger()
@@ -113,18 +128,22 @@ def set_verbosity(verbosity: int) -> None:
 
 
 def set_verbosity_info():
+    """Set the verbosity to the :obj:`INFO` level."""
     return set_verbosity(INFO)
 
 
 def set_verbosity_warning():
+    """Set the verbosity to the :obj:`WARNING` level."""
     return set_verbosity(WARNING)
 
 
 def set_verbosity_debug():
+    """Set the verbosity to the :obj:`DEBUG` level."""
     return set_verbosity(DEBUG)
 
 
 def set_verbosity_error():
+    """Set the verbosity to the :obj:`ERROR` level."""
     return set_verbosity(ERROR)