Is it possible to add to a string based on user input python

user_18882311 0
Viewed 80

I am currently working on a program that takes in user inputs, and depending on that users input the string should change. I was wondering if there was a way I could alter the string once the user input has been received. The following is a sample code.

title = input('Title: ')
subtitle = input('Subtitle: ')
chapter = input('Chapter: ')
subchapter = input('Subchapter: ')

title1 = '/title{}'.format(title)
subtitle1 = '/subtitle{}'.format(subtitle)
chapter1 = '/chapter{}'.format(chapter)
subchapter1 = '/subchapter{}'.format(subchapter)

output_txt = title1+subtitle1+chapter1+subchapter1
print(output_txt)
  1. Input taken by user: Should be a number
  2. The input would then be formatted to its perspective string
  3. Based on the user input the string, output_txt, should be formatted accordingly

Scenario 1: User Input

Title: 4
Subtitle:
Chapter: 12
Subchapter: 1

output_txt should be

output_txt = '/title4/chapter12/subchapter1'

Scenario 2: User Input

Title: 9
Subtitle: 
Chapter: 2
Subchapter:

output_txt should be

output_txt = '/title9/chapter2'

I have been using if elif but since there could be multiple combinations I do not think doing it that way is the most efficient.

Any help or tips in the right direction is greatly appreciated

user-input python-3.x python string
5 Answers

You could use an if-else condition while assigning string values to the variable

title = input('Title: ')
subtitle = input('Subtitle: ')
chapter = input('Chapter: ')
subchapter = input('Subchapter: ')

title1 = '/title{}'.format(title) if title else ''
subtitle1 = '/subtitle{}'.format(subtitle) if subtitle else ''
chapter1 = '/chapter{}'.format(chapter) if chapter else ''
subchapter1 = '/subchapter{}'.format(subchapter) if subchapter else ''

output_txt = title1+subtitle1+chapter1+subchapter1
print(output_txt)
user_143551350

Let me introduce you to typer

typer will help you to create a CLI with python easily

for your code can be approached like this

import typer

# By defining the data type, we can set the input only a number
def main(title: int = None, subtitle: int = None, chapter: int = None, subchapter: int = None):
    title = f'/title{title}' if title else ''
    subtitle = f'/subtitle{subtitle}' if subtitle else ''
    chapter = f'/chapter{chapter}' if chapter else ''
    subchapter = f'/subchapter{subchapter}' if subchapter else ''

    output_txt = title+subtitle+chapter+subchapter
    print(output_txt)


if __name__ == "__main__":
    typer.run(main)

And you just need to run it by adding the parameter for each one you need

python script_name.py --title 5 --chapter 2 --subchapter 7
user_43651430

Just for completeness you might want to test for a number as well.

# Test

def test_for_int(testcase):
    try:
        int(testcase)
        return True
    except ValueError: # Strings
        return False
    except TypeError: # None
        return False

# Get the inputs

title = input('Title: ')
subtitle = input('Subtitle: ')
chapter = input('Chapter: ')
subchapter = input('Subchapter: ')

# Run the tests and build the string

output_txt = ''
if test_for_int(title):
    output_txt += '/title{}'.format(title)
if test_for_int(subtitle):
    output_txt += '/subtitle{}'.format(subtitle)
if test_for_int(chapter):
    output_txt += '/chapter{}'.format(chapter)
if test_for_int(subchapter):
    output_txt += '/subchapter{}'.format(subchapter)
    
print(output_txt)
user_182084380

You can do something like this...

def get_user_input(message):
    user_input = input(message+' : ')
    if user_input == '' or user_input.isdigit() == True:
        return user_input
    else:
        return False


def f():
    title   = ''
    while True:
        title = get_user_input('title')
        if title == False:
            continue
        else:
            break



    subtitle   = ''
    while True:
        subtitle = get_user_input('subtitle')
        if subtitle == False:
            continue
        else:
            break


    chapter   = ''
    while True:
        chapter = get_user_input('chapter')
        if chapter == False:
            continue
        else:
            break

    subchapter   = ''
    while True:
        subchapter = get_user_input('subchapter')
        if subchapter == False:
            continue
        else:
            break

    s  = ''
    s += '/title'+str(title) if title != '' else ''
    s += '/subtitle'+str(subtitle) if subtitle != '' else ''
    s += '/chapter'+str(chapter) if chapter != '' else ''
    s += '/subchapter'+str(subchapter) if subchapter != '' else ''

    return s

Output...

title : 1
subtitle : 2
chapter : 3
subchapter : 4

'/title1/subtitle2/chapter3/subchapter4'

title : 1
subtitle : 
chapter : 3
subchapter : 

'/title1/chapter3'

Obviously you need to add few changes to the code for your specific purpose.

user_73028890

Here's an approach that uses a regular expression for input validation and list comprehensions to gather the inputs and build the output string.

import re


def get_input( label: str = None ) -> int:
    entry = input(label + ': ')

    if re.match(r'^\d+$', entry) is None:
        return None

    if int(entry) <= 0:
        return None

    return int(entry)


tpl_labels = ('Title', 'Subtitle', 'Chapter', 'Subchapter')

lst_values = [get_input(x) for x in tpl_labels]

output_txt = '/'.join([f'{x.lower()}{y}' for x, y in zip(tpl_labels, lst_values) if y])

if not output_txt:
    print('No valid responses given.')
else:
    output_txt = '/' + output_txt
    print(output_txt)

The get_input() function expects each value entered by the user to be a positive integer. All other input is silently ignored (and None is returned).

user_2386990
Related