How to take exact number of inputs from the user using Python?

Question

I am relatively new to programming and especially to Python. I am asked to create a for loop which prints 10 numbers given by the user. I know how to take input and how to create a for loop. What bothers me, is the fact that with my program I rely on the user to insert 10 numbers. How can I make the program control how many numbers are inserted? Here is what I tried:

x = input('Enter 10 numbers: ')
for i in x:
    print(i)

There are a bunch of different ways to do this: my preferred option would be to use a for loop. Make a for loop that loops 10 times (`for _ in range(9):`) and each time record your input in a list. I'm not sure what the parameters are for our assignment, but if you need to do validation on the input, look [here](https://stackoverflow.com/questions/23294658/asking-the-user-for-input-until-they-give-a-valid-response). — Christian Dean, Dec 01 '19 at 20:41
here you go https://stackoverflow.com/q/17647907/5986907 though it's a not a duplicate as such — joel, Dec 01 '19 at 20:42

score 1 · Accepted Answer · answered Dec 01 '19 at 20:58

1

You need to

ask 10 times : make a loop of size 10
ask user input : use the input function

for i in range(10):
    choice = input(f'Please enter the {i+1}th value :')

If you want to keep them after, use a list

choices = []
for i in range(10):
    choices.append(input(f'Please enter the {i + 1}th value :'))

# Or with list comprehension
choices = [input(f'Please enter the {i + 1}th value :') for i in range(10)]

answered Dec 01 '19 at 20:58

azro

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Thank you for your quick response. What does the f exactly do? I assume it is something like a counter, right? – Hristo Georgiev Dec 01 '19 at 23:10
@HristoGeorgiev It denotes an f-string, which is a new method for string formatting in Python. – AMC Dec 02 '19 at 01:05
@HristoGeorgiev f-strings are a shorter way of `"{} {}".format(obja, objb)` you insert directly the value into quotes – azro Dec 02 '19 at 06:36
@HristoGeorgiev you can now think about accepting the answer / vote up too ;) – azro Dec 02 '19 at 14:48
@azro What do you mean? I voted up your solution. I signed up to the site yesterday hah. – Hristo Georgiev Dec 02 '19 at 21:46

score 1 · Answer 2 · answered Dec 01 '19 at 21:35

What if input is row that contains word (numbers) separated by spaces? I offer you to check if there are 10 words and that they are numbers for sure.

import re
def isnumber(text):
   # returns if text is number ()
   return re.match(re.compile("^[\-]?[1-9][0-9]*\.?[0-9]+$"), text)

your_text = input() #your input
splitted_text = your_text.split(' ') #text splitted into items

# raising exception if there are not 10 numbers:
if len(splitted_text) != 10:
    raise ValueError('you inputted {0} numbers; 10 is expected'.format(len(splitted_text)))

# raising exception if there are any words that are not numbers
for word in splitted_text:
    if not(isnumber(word)):
        raise ValueError(word + 'is not a number')

# finally, printing all the numbers
for word in splitted_text:
    print(word)

I borrowed number checking from this answer

How to take exact number of inputs from the user using Python?

2 Answers2