improve your python code(2)

#!/usr/bin/env python
# -*- coding: UTF-8 -*-
"""
@author: XiangguoSun
@contact: sunxiangguodut@qq.com
@file: suggest2.py
@time: 2017/5/2 10:46
@software: PyCharm
"""
# ex1: 三元操作符 condition? value1:value2
x = 0
y = -2
z = x if x < y else y

# ex2: switch...case
# method1:
n = 2
if n == 0:
    print('Your typed 0.\n')
elif n == 1:
    print('Your typed 0.\n')
elif n == 2:
    print('Your typed 2.\n')
else:
    print('Only single-digit accept.\n')


# method2:
def switch(case):
    """
    switch-case code block
    :param case: your case
    :return: specific function in your case
    """
    return {
        0: 'Your typed 0.\n',
        1: 'Your typed 1.\n',
        2: 'Your typed 2.\n'
    }.get(case, 'Only single-digit accept.\n')      # get your input case and decide which function to do.

print(switch(1))

#!/usr/bin/env python
# -*- coding: UTF-8 -*-
"""
@author: XiangguoSun
@contact: sunxiangguodut@qq.com
@file: const.py
@time: 2017/5/2 11:43
@software: PyCharm
"""
class _const:
    class ConstError(TypeError):
        pass

    class ConstCaseError(ConstError):
            pass

    def __setattr__(self, name, value):
        if name in self.__dict__:
            raise(self.ConstError, "Can't change const.{name}".format(name=name))
        if not name.isupper():
            raise(self.ConstCaseError, "const name {name} is not all uppercase".format(name=name))
        self.__dict__[name] = value

import sys
sys.modules[__name__] = _const()

#!/usr/bin/env python
# -*- coding: UTF-8 -*-
"""
@author: XiangguoSun
@contact: sunxiangguodut@qq.com
@file: constant.py
@time: 2017/5/2 11:30
@software: PyCharm
"""
import const

const.MY_CONSTANT = 1

#!/usr/bin/env python
# -*- coding: UTF-8 -*-
"""
@author: XiangguoSun
@contact: sunxiangguodut@qq.com
@file: TEST.py
@time: 2017/5/2 11:42
@software: PyCharm
"""
from constant import const
print(const.MY_CONSTANT)