list_operation.py

import os
import sys

class InvalidListSize(Exception):
    "Raised when the input string length is not a multiple of 10"
    pass

def process_user_list(input):
    try:
        user_list = input.split()
        size = len(user_list)
        if size % 10 != 0 or size == 0:
            raise InvalidListSize
        else:
            for i in range(size):
                # convert each item to int type
                user_list[i] = int(user_list[i])
            # remove values from indices which are multiple of 2 or 3
            new_list = [value for index, value in enumerate(user_list) if (index + 1) % 2 != 0 and (index + 1) % 3 != 0]
            print("New list :", new_list)

    except InvalidListSize:
        print("List size is not a multiple of 10")
    except ValueError:
        print("The input was not a valid integer.")

# Get input from environment variable
input_string = os.environ.get('INPUT_STRING', '')

# If input is not provided through environment variable, wait for user input
if not input_string and sys.stdin.isatty():
    input_string = input('Enter elements of a list separated by space:\n')

process_user_list(input_string)