Evuraan wrote:
> Greetings!
>
>
> #!/usr/bin/python3
> class Employee:
> """Class with FirstName, LastName, Salary"""
> def __init__(self, FirstName,LastName, Salary):
> self.FirstName = FirstName
> self.LastName = LastName
> self.Salary = Salary
> def __str__(self):
> return '("{}" "{}" "{}")'.format(self.FirstName,
> self.LastName, self.Salary)
> class Developer(Employee):
> """Define a subclass, augment with ProgLang"""
> def __init__(self, FirstName,LastName, Salary, ProgLang):
> Employee.__init__(self, FirstName,LastName, Salary)
> self.ProgLang = ProgLang
> def dev_repr(self):
> return '("{}" "{}" "{}" "{}")'.format(self.FirstName,
> self.LastName, self.Salary, self.ProgLang)
> a = Employee("Abigail", "Buchard", 83000)
> print(a)
> dev_1 = Developer("Samson", "Sue", 63000, "Cobol",)
> print(dev_1)
> print(dev_1.dev_repr())
>
> running that yields,
>
> ("Abigail" "Buchard" "83000")
> ("Samson" "Sue" "63000")
> ("Samson" "Sue" "63000" "Cobol")
>
> My doubt is, how can we set the __str__ method work on the Employee
> subclass so that it would show ProgLang too, like the
> print(dev_1.dev_repr())?
>
> Thanks in advance!
Here's an indirect approach that should be easy to understand and adapt --
provide a method that converts attributes into a tuple. Subclasses that
introduce new attributes can override this method, and __str__() uses
as_tuple() to get the instance data instead of accessing the attributes
directly:
$ cat tmp.py
#!/usr/bin/python3
def quote(value):
# have you thought about attributes containing a '"'?
return '"{}"'.format(value)
class Employee:
"""Class with FirstName, LastName, Salary"""
def __init__(self, FirstName, LastName, Salary):
self.FirstName = FirstName
self.LastName = LastName
self.Salary = Salary
def as_tuple(self):
return self.FirstName, self.LastName, self.Salary
def __str__(self):
strings = (quote(a) for a in self.as_tuple())
return "({})".format(" ".join(strings))
class Developer(Employee):
"""Define a subclass, augment with ProgLang"""
def __init__(self, FirstName, LastName, Salary, ProgLang):
super().__init__(FirstName, LastName, Salary)
self.ProgLang = ProgLang
def as_tuple(self):
return super().as_tuple() + (self.ProgLang,)
print(Employee("Abigail", "Buchard", 83000))
print(Developer("Samson", "Sue", 63000, "Cobol"))
$ python3 tmp.py
("Abigail" "Buchard" "83000")
("Samson" "Sue" "63000" "Cobol")
Another option builds on the assumption that attribute names match __init__
argument names (I've replaced quote() with repr() this time):
$ cat tmp2.py
#!/usr/bin/python3
import inspect
class Employee:
"""Class with FirstName, LastName, Salary"""
def __init__(self, FirstName, LastName, Salary):
self.FirstName = FirstName
self.LastName = LastName
self.Salary = Salary
def __str__(self):
names = inspect.getargspec(self.__init__).args[1:]
values = (getattr(self, name) for name in names)
return "({})".format(" ".join(map(repr, values)))
class Developer(Employee):
"""Define a subclass, augment with ProgLang"""
def __init__(self, FirstName, LastName, Salary, ProgLang):
super().__init__(FirstName, LastName, Salary)
self.ProgLang = ProgLang
print(Employee("Abigail", "Buchard", 83000))
print(Developer("Samson", "Sue", 63000, "Cobol"))
$ python3 tmp2.py
('Abigail' 'Buchard' 83000)
('Samson' 'Sue' 63000 'Cobol')
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