是否存在定义全部月份常量的Python标准模块？

calendar模块定义了星期几的常量，例如MONDAY（0）、TUESDAY（1）等。此外，它的源代码中定义了（但未导出）January（1）和February（2）的常量，但没有定义其余月份的常量。

虽然可以自行在模块中补充这些定义，但这类需求较为常见，因此产生疑问：是否存在定义所有月份常量的Python标准模块？

解答 #

Python标准库中没有专门导出所有月份数值常量的模块。不过可以通过以下方式实现类似需求：

• 使用calendar模块的month_name或month_abbr属性获取月份名称列表，例如calendar.month_name[1]对应"January"，calendar.month_name[12]对应"December"
• 自行定义月份常量，比如：

  JANUARY = 1
  FEBRUARY = 2
  MARCH = 3
  APRIL = 4
  MAY = 5
  JUNE = 6
  JULY = 7
  AUGUST = 8
  SEPTEMBER = 9
  OCTOBER = 10
  NOVEMBER = 11
  DECEMBER = 12
  

• 结合enum模块创建月份枚举类，增强可读性：

  from enum import IntEnum
  
  class Month(IntEnum):
      JANUARY = 1
      FEBRUARY = 2
      MARCH = 3
      APRIL = 4
      MAY = 5
      JUNE = 6
      JULY = 7
      AUGUST = 8
      SEPTEMBER = 9
      OCTOBER = 10
      NOVEMBER = 11
      DECEMBER = 12
  

内容的提问来源于stack exchange，提问作者Juan A. Navarro