single data type string in python3

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single data type string in python3

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#1 by (2 votes)

1

Pythonist friends, as a newbie and trying to learn about programming in python, I would like help on how to get only data string (name) in a function, and not allow me to continue if I do not type text. my code is:

class Nomina:
    def __init__(self):
        self.nombre_empleado = ""

    def ObtenerDatos (self):
        if(type(self.nombre_empleado == str)):
            self.nombre_empleado = str(input("EL NOMBRE DEL EMPLEADO ES : "))
        else:
            print("pasa")


    def mostrarDatos (self):
        print("-----------------------------------------")
        print("LOS DATOS PARA SU LIQUIDACION SON :")
        print("-----------------------------------------")
        print("Nombre del Empleado :", self.nombre_empleado)

and this the result:

EL NOMBRE DEL EMPLEADO ES : 445    
-----------------------------------------    
LOS DATOS PARA SU LIQUIDACION SON :    
-----------------------------------------    
>Nombre del Empleado : 445    

Process finished with exit code 0

and despite typing a data type inetgrer or whole receives it and continues the execution. How do I make it so that it only allows typing text type and not continue if I do not type the string?

python python-3.x

asked by Jsierra2017 02.06.2017 в 19:09

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1 answer

object reference not set to an instance of an object [duplicate] ROLLBACK TRANSACTION without the corresponding BEGIN TRANSACTION

score 2 · Accepted Answer

In Python 3.x input always return a string. You do not need to cast str , it already is. If you want the input to not contain numeric characters you must validate the chain and act accordingly (throwing an exception or asking for the data again). Depending on what you want you can use str.isalpha , str.isnumeric() or regular expressions for more complex things.

class Nomina:
    def __init__(self):
        self.nombre_empleado = ""

    def obtenerDatos (self):
        nombre = input("EL NOMBRE DEL EMPLEADO ES : ")
        if nombre.isalpha():
            self.nombre_empleado = nombre
        else:
            print("pasa")


    def mostrarDatos (self):
        print("-----------------------------------------")
        print("LOS DATOS PARA SU LIQUIDACION SON :")
        print("-----------------------------------------")
        print("Nombre del Empleado :", self.nombre_empleado)

In this case with isalpha any text entered that contains a character that is not between A-Z and a-z including the space will be invalid. With isnumeric texts like 'Ramon1' are valid but not '123' would not be.

Generally the most flexible option is regular expressions, for example, to validate names of the type 'Antonio Jesús Cañamero' you will need to include the accents, the ñ and the spaces in the validation:

import re

class Nomina:
    def __init__(self):
        self.nombre_empleado = ""

    def obtenerDatos (self):
        nombre = input("EL NOMBRE DEL EMPLEADO ES : ")
        if re.match("^[A-Za-z áéíóúÁÉÍÓÚñÑ]*$", nombre):
            self.nombre_empleado = nombre
        else:
            print("pasa")


    def mostrarDatos (self):
        print("-----------------------------------------")
        print("LOS DATOS PARA SU LIQUIDACION SON :")
        print("-----------------------------------------")
        print("Nombre del Empleado :", self.nombre_empleado)

a = Nomina()
a.obtenerDatos()

You can create your customized expression to accept or not other things like _ , - , @ , . , , etc.

Edit:

If you want to ask for the name until it is valid you must use an infinite cycle to ask for input until it is validated:

import re

class Nomina:
    def __init__(self):
        self.nombre_empleado = ""

    def obtenerDatos (self): 
        while not self.nombre_empleado:
            nombre = input("EL NOMBRE DEL EMPLEADO ES : ")
            if re.match("^[A-Za-z áéíóúÁÉÍÓÚñÑ]*$", nombre):
                self.nombre_empleado = nombre
            else:
                print("NOMBRE INVÁLIDO")


    def mostrarDatos (self):
        print("-----------------------------------------")
        print("LOS DATOS PARA SU LIQUIDACION SON :")
        print("-----------------------------------------")
        print("Nombre del Empleado :", self.nombre_empleado)

a = Nomina()
a.obtenerDatos()