Maintain backwards compatibility

Author: nhairs

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "python-json-logger"
-version = "4.0.0.dev1"
+version = "3.1.0.dev1"
 description = "JSON Log Formatter for the Python Logging Package"
 authors = [
     {name = "Zakaria Zajac", email = "zak@madzak.com"},

src/pythonjsonlogger/__init__.py

@@ -4,10 +4,12 @@
 
 ## Standard Library
 import sys
+import warnings
 
 ## Installed
 
 ## Application
+import pythonjsonlogger.json
 
 ### CONSTANTS
 ### ============================================================================
@@ -22,3 +24,15 @@
         ORJSON_AVAILABLE = True
     except ImportError:
         ORJSON_AVAILABLE = False
+
+
+### DEPRECATED COMPATIBILITY
+### ============================================================================
+def __getattr__(name: str):
+    if name == "jsonlogger":
+        warnings.warn(
+            "pythonjsonlogger.jsonlogger has been moved to pythonjsonlogger.json",
+            DeprecationWarning,
+        )
+        return pythonjsonlogger.json
+    raise AttributeError(f"module {__name__} has no attribute {name}")