How to create an object by requesting data from the user and running from a function?

Question

I created a simple class, I can create an object, but I’m developing a CRUD that needs to create the object from a function. Look at my example:

class Funcionario:
    def __init__(self, nome, cargo, salario):
        self.nome = nome
        self.cargo = cargo
        self.salario = salario


def registrar():
    func = Funcionario(
        nome = input('Nome: '),
        cargo = input('Cargo: '),
        salario=(input('Salário: '))
    )

def modificar():
    func ?

The problem is that the creation of the object stays within the function, that is, it is not global.

If I try to create a method change in the class and I will run from a function edit the position, for example, how do I instantiate the object, being that it is in the other function? And if I leave out, he keeps calling all the time the creation of the object, which I don’t want.

---

Complete code:

class Funcionario:
    def __init__(self, nome, cargo, salario):
        self.nome = nome
        self.cargo = cargo
        self.salario = salario
    
    def altera_cargo(self):
        novo_cargo = input('Novo cargo: ')
        self.cargo = novo_cargo
        print('Cargo atualizado para {}'.format(self.cargo))
    
    def altera_salario(self):
        novo_salario = float(input('Novo salário: '))
        self.salario = novo_salario
        print('Salário atualizado para R$ {}'.format(self.salario))


def registra():
    return Funcionario(
        nome = input('Nome: '),
        cargo = input('Cargo: '),
        salario = float(input('Salário: '))
    )


def menu():
    opcao = int(input('1. Novo\n2. Editar cargo\n3. Editar salário\n--> '))

    if opcao == 1:
        registra()
        print('\n')
        menu()
    if opcao == 2:
        altera_cargo() # como acessar o objeto ?
        print('\n')
        menu()
    if opcao == 3:
        altera_salario() # como acessar o objeto ?
        print('\n')
        menu()
    else:
        exit()

if __name__ == "__main__":
    menu()

Answer 1

Just make the function return the employee who was created. Then you pass this employee to the function you modify, and inside you change the data you need. Ex:

def registrar(): # retorna um novo funcionario
    return Funcionario(
        nome = input('Nome: '),
        cargo = input('Cargo: '),
        salario = float(input('Salário: '))
    )

def modificar(func): # modifica os dados de um funcionário
    func.salario = float(input('Novo salário:'))
    func.cargo = input('Novo cargo:')
    # etc...

# registra um funcionário e modifica
funcionario = registrar()
modificar(funcionario)

# registra outro funcionário e modifica
outro_funcionario = registrar()
modificar(outro_funcionario)

etc...

The return causes the value to be returned to whoever called the function. Thus, each call to registrar returns a new instance of Funcionario, that you can handle separately.

And the function modificar receives an employee as a parameter, and inside it modifies the data of this.

Note: I used float to convert the salary to a number, because it seems to me that it does not make sense the salary to be a string (just remembering that will give error if it is not typed a number).

---

Now, if the idea is to call the employee’s own methods, then first you need to create it.

And if you want to keep repeating the menu several times, don’t call the function within itself. Instead, do a loop infinite and interrupt it using break:

def menu():
    func = None
    while True:
        opcao = int(input('1. Novo\n2. Editar cargo\n3. Editar salário\n--> '))
        if opcao == 1:
            func = registra()
        elif opcao == 2:
            if func is None:
                print('funcionário ainda não foi criado')
            else:
                func.altera_cargo()
        elif opcao == 3:
            if func is None:
                print('funcionário ainda não foi criado')
            else:
                func.altera_salario()
        else:
            break # sai do loop
        print('\n')

I mean, I have an employee func which at first has no value (None). When registering, the function registra() returns this employee, and once having him, I can call the methods of it (altera_cargo and altera_salario).

Look at the while True, he keeps repeating everything until he finds one break (the difference is that exit leaves the program, now break interrupts only the while, so if there was any code after him, this one would run).

That’s better than what you did, 'cause you keep calling the function menu within itself (which is called recursion) can cause a stack overflow. Prefer to use a loop, who doesn’t have that problem.