How to get user input within a Method (python)

Question

I'm still learning how to work within classes. I'm trying to get user input from the user using self methods (Training exercises).

Here is my code (I just want to get the user input and display it, but with using methods)

import os
import time

class Programs: 
        def basicintro(self):
                print "Welcome to the BMR Calculator"
                time.sleep(1)      
        def createname(self,name):
                self.name = name
        def ask(self):
                while name == "":
                        name = raw_input("Name:")
                        if name != "":
                                print "Hello", name
                                time.sleep(1)
                        else:
                                print name                
def main():
        object1 = Programs()
        object1.basicintro()
        object1.createname()
        object1.ask()    
        raw_input("\n\nPress enter to exit.")          
main()

I basically just want to ask the user to input their name and then make their name an object so if i need it later in the program, I can just call it

so what problem are you facing.? – RanRag Jan 28 '12 at 00:42 — RanRag, Jan 28 '12 at 00:42
use setattr(self, func_name, function) – Joel Cornett Jan 28 '12 at 06:27 — Joel Cornett, Jan 28 '12 at 06:27

Brigand · Answer 1 · 2012-01-28T00:49:33.867

In the ask method, each time name is written, it should be self.name.

For example:

while name == "":
# to
while self.name == "":

In your main function, object1.createname() will give an error. It's expecting two parameters. The implicit, called object1 outside the function, and self inside, is being passed. You don't, however, give a value for name.

object1.createname("Joe")

These lines are only executed when name is a blank string. So print '\n' will do the same thing. Leaving it out will just make one "Name:" on each line until valid input is given.

else:
    print self.name # "self." added

Consider defining an init method, which takes a name. That way you can set one when the class is created. You can also give a default value, which won't affect your current calling (it's optional, so if you want to give a name later, you can.

def __init__(self, name="SomeDefaultName"):
   pass # Content here

I edited and added 3 times more information than I already had. — Brigand, Jan 28 '12 at 00:50
Thanks for the help, I'm going to read more into the __init__. — hijaked79, Jan 28 '12 at 17:54

score 1 · Accepted Answer · edited May 23 '17 at 12:00

I'd say that there are a couple of problems in your code:

First you need a good input cycle, I'll use a simple one:

while 1: # infinite loop
    name = raw_input("Name: ")
    if name == "":
        print "Ops! Retry"
    else:
        print "Hello", name
        break  # this will break the loop

Let's put this cycle inside your class:

class Programs:

    def ask(self):
        while 1: # infinite loop
            name = raw_input("Name: ")
            if name == "":
                print "Ops! Retry"
            else:
                print "Hello", name
                break  # this will break the loop

For what I understand you want to store the name provided by the user as an attribute of of your Program class instance, so:

class Programs:

    def __init__(self):  # class constructur (called at creation time)
        self.name = ""   # the default name is the empty string

    def ask(self):
        while 1: # infinite loop
            name = raw_input("Name: ")
            if name == "":
                print "Ops! Retry"
            else:
                print "Hello", name
                break  # this will break the loop

        self.name = name  # assign to self.name the value name

Example:

>>> prog = Programs()
>>> prog.name
''
>>> prog.ask()
Name: Rik
Hello Rik
>>> prog.name
'Rik'

As you can see the method __init__ was called immediatly and placed assigned the empty string to prog.name.

If you want to put that example code inside your script, this is how to do it:

class Programs:

    def __init__(self):  # class constructur (called at creation time)
        self.name = ""   # the default name is the empty string

    def ask(self):
        while 1: # infinite loop
            name = raw_input("Name: ")
            if name == "":
                print "Ops! Retry"
            else:
                print "Hello ", name
                break  # this will break the loop

        self.name = name  # assign to self.name the value name


if __name__ == '__main__':
    prog = Programs()
    prog.ask()
    raw_input("\n\nPress enter to exit.")

If you want, you can put that code inside a function, but what I wanted to show the use of if __name__ == '__main__':. Information can be found in this well answered question.

Thank you both for your input! Makes sense now, I was kinda afraid to start throwing around the __init__. I understand what you did. I guess i had a general idea, but my placement was off. — hijaked79, Jan 28 '12 at 05:17
@hijaked79: You're welcome! When you find an answer that is useful (like I presume you find this one) you can also up-vote it, that would be appreciated :) — Rik Poggi, Jan 28 '12 at 09:29

How to get user input within a Method (python)

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