try completo

#!/usr/bin/env python
# -*- coding: utf-8 -*-
#
"""
def sumar(a,b):
    if not isinstance(a, (float,int)) or not isinstance(b, (float,int)):
        raise TypeError("Los argumentos deben ser numéricos")
    return a+b


print(sumar(2,3))
print(sumar("Hola","Chau"))
print(sumar((2,3),(4,5)))
"""
try:
    f = open("uno.txt","x")
except FileExistsError:
    f = open("uno.txt", "a")
else:
    print("Se creó un nuevo archivo...")
finally:
    f.write("Chau\n")
    f.close()