Get a List of Numbers as Input from the User

Get a list of numbers as input from the user

In Python 3.x, use this.

a = [int(x) for x in input().split()]

Example

>>> a = [int(x) for x in input().split()]
3 4 5
>>> a
[3, 4, 5]
>>> 

How to input numbers of a list individually from user input?

Try this.

I am using f-strings here. This only works in Python 3.6+.

n = int(input('How many numbers do you want to add to the list? '))
lst = []
for i in range(1,n+1):
    temp = int(input(f'Number {i}: '))
    lst.append(temp)

print(f'List:\n{lst}')

Output:

How many numbers do you want to add to the list? 5

Number 1: 67
Number 2: 6
Number 3: 45
Number 4: 9
Number 5: 1

List:
[67, 6, 45, 9, 1]

How to input list of number from users and output the numbers on console in Dart

import 'dart:io';

void main(List<String> arguments) {
  var arr = <int>[];
  var i = 0;
  
  while (i < 10) {
    stdout.write('Enter #${i+1}: ');
    var x = stdin.readLineSync();
    if (x == null) continue;
    var n = int.tryParse(x);
    if (n == null) continue;
    arr.add(n);
    i++;
  }
  print('\nMy numbers: $arr');
}

Output:

Enter #1: 2
Enter #2: 43
Enter #3: er
Enter #3: 45
Enter #4: 7
Enter #5: 5
Enter #6: -3
Enter #7: ñ
Enter #7: 5
Enter #8: 6
Enter #9: 87
Enter #10: 2

My numbers: [2, 43, 45, 7, 5, -3, 5, 6, 87, 2]

Get user input as a list of integers

Try something like:

user_input: list = list(map(int, input().split()))

We firstly grab an input(), eg. "1 2 3 4 5", then we split() it and we have ["1", "2", "3", "4", "5"], finally we map them into integers and convert to a list :)

number/numbers to list by using input()

In your function, you can directly convert num into a list by calling split(','), which will split on a comma - in the case a comma doesn't exist, you just get a single-element list. For example:

In [1]: num = '1'

In [2]: num.split(',')
Out[2]: ['1']

In [3]: num = '1,2,3,4'

In [4]: num.split(',')
Out[4]: ['1', '2', '3', '4']

You can then use your function as you have it:

def inputnumber():
    num = raw_input('Enter number(s): ').split(',')
    number = map(int,num)
    return number

x = inputnumber()
print x

However you can take it a step further if you want - map here can be replaced by a list comprehension, and you can also get rid of the intermediate variable number and return the result of the comprehension (same would work for map as well, if you want to keep that):

def inputnumber():
    num = raw_input('Enter number(s): ').split(',')
    return [int(n) for n in num]

x = inputnumber()
print x

If you want to handle other types of input without error, you can use a try/except block (and handle the ValueError exception), or use one of the fun methods on strings to check if the number is a digit:

def inputnumber():
    num = raw_input('Enter number(s): ').split(',')
    return [int(n) for n in num if n.isdigit()]

x = inputnumber()
print x

This shows some of the power of a list comprehension - here we say 'cast this value as an integer, but only if it is a digit (that is the if n.isdigit() part).

And as you may have guessed, you can collapse it even more by getting rid of the function entirely and just making it a one-liner (this is an awesome/tricky feature of Python - condensing to one-liners is surprisingly easy, but can lead to less readable code in some case, so I vote for your approach above :) ):

print [int(n) for n in raw_input('Number(s): ').split(',') if n.isdigit()]

---

Related Topics