Activestate有一个由古老的Alex
Martelli撰写的题为“ Constants in
Python ”的食谱
，
用于创建具有创建后无法反弹的属性的模块。听起来像您在寻找什么，除了大写字母-
但这可以通过检查属性名称是否全部大写来添加。
const
当然，这可以由有决心的人规避，但这就是Python的方式—并被大多数人视为“好事”。但是，要使其变得更困难一点，我建议您不要去添加所谓的显而易见的
__delattr__方法，因为人们可以随后删除名称，然后将其重新添加回不同的值。
这就是我要采取的措施：
# Put in const.py...# from http://pre.activestate.com/recipes/65207-constants-in-pythonclass _const: class ConstError(TypeError): pass # base exception class. class ConstCaseError(ConstError): pass def __setattr__(self, name, value): if name in self.__dict__: raise self.ConstError("Can't change const.%s" % name) if not name.isupper(): raise self.ConstCaseError('const name %r is not all uppercase' % name) self.__dict__[name] = value# Replace module entry in sys.modules[__name__] with instance of _const# (and create additional reference to it to prevent its deletion -- see# https://stackoverflow.com/questions/5365562/why-is-the-value-of-name-changing-after-assignment-to-sys-modules-name)import sys_ref, sys.modules[__name__] = sys.modules[__name__], _const()if __name__ == '__main__': import __main__ as const # Test this module... try: const.Answer = 42 # Not OK to create mixed-case attribute name. except const.ConstCaseError as exc: print(exc) else: # Test failed - no ConstCaseError exception generated. raise RuntimeError("Mixed-case const names should't be allowed!") try: const.ANSWER = 42 # Should be OK, all uppercase. except Exception as exc: raise RuntimeError("Defining a valid const attribute should be allowed!") else: # Test succeeded - no exception generated. print('const.ANSWER set to %d raised no exception' % const.ANSWER) try: const.ANSWER = 17 # Not OK, attempt to change defined constant. except const.ConstError as exc: print(exc) else: # Test failed - no ConstError exception generated. raise RuntimeError("Shouldn't be able to change const attribute!")输出：
const name 'Answer' is not all uppercaseconst.ANSWER set to 42 raised no exceptionCan't change const.ANSWER
