Add support for ExceptionGroup backport (through "exceptiongroup" lib)

loguru/_better_exceptions.py

@@ -16,9 +16,17 @@ def is_exception_group(exc):
         return isinstance(exc, ExceptionGroup)
 
 else:
+    try:
+        from exceptiongroup import ExceptionGroup
+    except ImportError:
 
-    def is_exception_group(exc):
-        return False
+        def is_exception_group(exc):
+            return False
+
+    else:
+
+        def is_exception_group(exc):
+            return isinstance(exc, ExceptionGroup)
 
 
 class SyntaxHighlighter:

setup.py

@@ -73,6 +73,7 @@
             "colorama==0.4.6 ; python_version>='3.8'",
             "freezegun==1.1.0 ; python_version<'3.8'",
             "freezegun==1.2.2 ; python_version>='3.8'",
+            "exceptiongroup==1.1.3 ; python_version>='3.7' and python_version<'3.11'",
             # Type checking.
             "mypy==v0.910 ; python_version<'3.6'",
             "mypy==v0.971 ; python_version>='3.6' and python_version<'3.7'",

tests/test_exceptions_formatting.py

@@ -248,3 +248,21 @@ def test_exception_modern(filename, minimum_python_version):
         pytest.skip("Feature not supported in this Python version")
 
     compare_exception("modern", filename)
+
+
+@pytest.mark.skipif(
+    not (3, 7) <= sys.version_info < (3, 11), reason="No backport available or needed"
+)
+def test_group_exception_using_backport(writer):
+    from exceptiongroup import ExceptionGroup
+
+    from loguru import logger
+
+    logger.add(writer, backtrace=True, diagnose=True, colorize=False, format="")
+
+    try:
+        raise ExceptionGroup("Test", [ValueError(1), ValueError(2)])
+    except Exception:
+        logger.exception("")
+
+    assert writer.read().strip().startswith("+ Exception Group Traceback (most recent call last):")