how to read array elements from user in python

Question

I am trying to read array elements as

4 #no. of elements to be read in array
1 2 3 4 

what i have tried by referring other answers

def main():

    n=int(input("how many number you want to enter:"))
    l=[]
    for i in range(n):
        l.append(int(input()))

this works fine if i give input as

4 #no. of elements to be read
1
2
3
4

but if i try to give like

4 #no. of element to be read

1 2 3 4

I get error as:

ValueError: invalid literal for int() with base 10: '1 2 3 4'

Please help me with this

Answer 1

Since there's no input delimiters in Python, you should use split and split the input that you've received from the user:

lst = your_input.split()

Answer 2

Your first approach is OK, for the second way use this:

n=int(input("how many number you want to enter:"))
l=map(int, input().split())[:n] # l is now a list of at most n integers

This will map the function int on the split parts (what split gives) of the user input (which are 1, 2, 3 and 4 in your example.

It also uses slicing (the [:n] after map) to slice in case the user put more integers in.

Answer 3

The input() function returns a string that the user enters. The int() function expects to convert a number as a string to the corresponding number value. So int('3') will return 3. But when you type in a string like 1 2 3 4 the function int() does not know how to convert that.

You can either follow your first example:

    n = int(input('How many do you want to read?'))
    alist = [] 

    for i in range(n):
        x = int(input('-->'))
        alist.append(x)

The above requires you to only enter a number at a time.

Another way of doing it is just to split the string.

    x = input('Enter a bunch of numbers separated by a space:')
    alist = [int(i) for i in x.split()]

The split() method returns a list of numbers as strings excluding the spaces

Answer 4

n = input("how many number you want to enter :")

l=readerinput.split(" ")