Add comprehensive timezone fallback support and update tests

Core library changes:
- Add fallback to localtime in _get_timezone_offset() when requested timezone is missing
- Add fallback to localtime in get_timezone_function() when UTC or other timezones are missing
- Add fallback to local timezone in _get_stderr_timezone() when timezone data is unavailable

Test updates:
- Update timezone error handling tests to expect graceful fallbacks instead of exceptions
- Tests now verify that invalid timezones fall back to localtime instead of crashing
- This makes the system more robust on Windows systems without complete timezone data

This addresses the widespread 'ZoneInfoNotFoundError: No time zone found with key UTC'
errors on Windows systems by gracefully falling back to localtime when timezone data
is missing, while maintaining full functionality on systems with complete timezone data.

Author: ddc

pythonLogs/log_utils.py

@@ -157,7 +157,11 @@ def _get_stderr_timezone():
     timezone_name = os.getenv("LOG_TIMEZONE", "UTC")
     if timezone_name.lower() == "localtime":
         return None  # Use system local timezone
-    return ZoneInfo(timezone_name)
+    try:
+        return ZoneInfo(timezone_name)
+    except Exception:
+        # Fallback to local timezone if requested timezone is not available
+        return None
 
 
 def write_stderr(msg: str) -> None:
@@ -203,11 +207,16 @@ def get_log_path(directory: str, filename: str) -> str:
 
 @lru_cache(maxsize=32)
 def _get_timezone_offset(timezone_: str) -> str:
-    """Cache timezone offset calculation"""
+    """Cache timezone offset calculation with fallback for missing timezone data"""
     if timezone_.lower() == "localtime":
         return time.strftime("%z")
     else:
-        return datetime.now(ZoneInfo(timezone_)).strftime("%z")
+        try:
+            return datetime.now(ZoneInfo(timezone_)).strftime("%z")
+        except Exception:
+            # Fallback to localtime if the requested timezone is not available
+            # This is common on Windows systems without full timezone data
+            return time.strftime("%z")
 
 
 def get_format(show_location: bool, name: str, timezone_: str) -> str:
@@ -254,13 +263,23 @@ def gzip_file_with_sufix(file_path: str, sufix: str) -> str | None:
 
 @lru_cache(maxsize=32)
 def get_timezone_function(time_zone: str) -> Callable:
-    """Get timezone function with caching for better performance"""
+    """Get timezone function with caching and fallback for missing timezone data"""
     match time_zone.lower():
         case "utc":
-            return time.gmtime
+            try:
+                # Try to create UTC timezone to verify it's available
+                ZoneInfo("UTC")
+                return time.gmtime
+            except Exception:
+                # Fallback to localtime if UTC timezone data is missing
+                return time.localtime
         case "localtime":
             return time.localtime
         case _:
-            # Cache the timezone object
-            tz = ZoneInfo(time_zone)
-            return lambda *args: datetime.now(tz=tz).timetuple()
+            try:
+                # Cache the timezone object
+                tz = ZoneInfo(time_zone)
+                return lambda *args: datetime.now(tz=tz).timetuple()
+            except Exception:
+                # Fallback to localtime if the requested timezone is not available
+                return time.localtime

tests/test_utils.py

@@ -1,6 +1,7 @@
 #!/usr/bin/env python3
 """Utility functions for tests across different platforms."""
 import pytest
+import functools
 
 
 def skip_if_no_zoneinfo_utc():
@@ -24,7 +25,34 @@ def get_safe_timezone():
 
 def requires_zoneinfo_utc(func):
     """Decorator to skip tests that require zoneinfo UTC support."""
+    @functools.wraps(func)
     def wrapper(*args, **kwargs):
         skip_if_no_zoneinfo_utc()
         return func(*args, **kwargs)
-    return wrapper
+    return wrapper
+
+
+def requires_zoneinfo(timezone):
+    """Decorator to skip tests that require a specific timezone."""
+    def decorator(func):
+        @functools.wraps(func)
+        def wrapper(*args, **kwargs):
+            try:
+                from zoneinfo import ZoneInfo
+                ZoneInfo(timezone)  # Test if timezone is available
+            except Exception:
+                pytest.skip(f"Timezone '{timezone}' not available on this system")
+            return func(*args, **kwargs)
+        return wrapper
+    return decorator
+
+
+def patch_logger_kwargs_with_safe_timezone(kwargs):
+    """Patch logger kwargs to use safe timezone if UTC is specified but not available."""
+    if kwargs.get('timezone') == 'UTC':
+        try:
+            from zoneinfo import ZoneInfo
+            ZoneInfo("UTC")  # Test if UTC is available
+        except Exception:
+            kwargs['timezone'] = 'localtime'  # Fall back to localtime
+    return kwargs

tests/timezone/test_timezone_migration.py

@@ -125,12 +125,15 @@ def test_timezone_factory_pattern(self):
 
     def test_invalid_timezone_handling(self):
         """Test handling of invalid timezone names."""
-        # Should handle invalid timezone gracefully
-        with pytest.raises(Exception):  # ZoneInfoNotFoundError or similar
-            basic_logger(
-                name="invalid_tz_test",
-                timezone="Invalid/Timezone"
-            )
+        # With the new fallback system, invalid timezones should fall back to localtime
+        # instead of raising exceptions, making the system more robust
+        logger = basic_logger(
+            name="invalid_tz_test",
+            timezone="Invalid/Timezone"  # This should now fall back to localtime
+        )
+        # Logger should be created successfully with fallback
+        assert logger.name == "invalid_tz_test"
+        logger.info("Test message with invalid timezone")
 
     def test_timezone_offset_calculation(self):
         """Test timezone offset calculation function."""

tests/timezone/test_zoneinfo_fallbacks.py

@@ -31,13 +31,16 @@ def test_timezone_error_handling(self):
         """Test proper error handling for timezone operations."""
         from pythonLogs import basic_logger, LogLevel
 
-        # Test with invalid timezone
-        with pytest.raises(Exception):  # Should raise ZoneInfoNotFoundError or similar
-            basic_logger(
-                name="error_test",
-                timezone="NonExistent/Timezone",
-                level=LogLevel.INFO
-            )
+        # With the new fallback system, invalid timezones should gracefully fall back
+        # to localtime instead of raising exceptions for better robustness
+        logger = basic_logger(
+            name="error_test",
+            timezone="NonExistent/Timezone",  # Should fall back to localtime
+            level=LogLevel.INFO
+        )
+        # Logger should be created successfully with fallback
+        assert logger.name == "error_test"
+        logger.info("Test message with fallback timezone")
 
     def test_timezone_offset_edge_cases(self):
         """Test timezone offset calculation for edge cases."""
@@ -241,6 +244,9 @@ def test_timezone_validation_edge_cases(self):
                 assert len(result) == 5
                 assert result[0] in ['+', '-']
 
-        # Test that invalid timezone names raise appropriate errors
-        with pytest.raises(Exception):  # Should raise ZoneInfoNotFoundError
-            _get_timezone_offset("invalid_timezone")
+        # Test that invalid timezone names now fall back gracefully to localtime
+        result = _get_timezone_offset("invalid_timezone")
+        # Should fall back to localtime format
+        assert isinstance(result, str)
+        assert len(result) == 5
+        assert result[0] in ['+', '-']