pythongh-103636: raise warning for January and February attribute

Lib/calendar.py

@@ -10,6 +10,7 @@
 from enum import IntEnum, global_enum
 import locale as _locale
 from itertools import repeat
+import warnings
 
 __all__ = ["IllegalMonthError", "IllegalWeekdayError", "setfirstweekday",
            "firstweekday", "isleap", "leapdays", "weekday", "monthrange",
@@ -41,6 +42,18 @@ def __str__(self):
         return "bad weekday number %r; must be 0 (Monday) to 6 (Sunday)" % self.weekday
 
 
+def __getattr__(name):
+    if name in ['January','February']:
+        warnings.warn(f"The '{name}' attribute is going to be deprecated use '{name.upper()}' instead",
+                        DeprecationWarning,
+                        stacklevel=2)
+        if name == 'January':
+            return JANUARY
+        else:
+            return FEBRUARY
+
+    raise AttributeError(f"module {__name__} has no attribute {name}")
+
 # Constants for months
 @global_enum
 class Month(IntEnum):
@@ -71,6 +84,7 @@ class Day(IntEnum):
 
 
 
+
 # Number of days per month (except for February in leap years)
 mdays = [0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]