# -*- coding: utf-8 -*-
"""
  Lab 7, Task 3

  Writing functions using loops
"""

def num_vowels(s):
    """  returns the number of vowels in a string s consisting
         of lower-case letters
    """
    count = 0
    
    for c in s:
        if c in 'aeiou':
            count += 1
            
    return count

def rem_all(elem, vals):
    """ returns a list in which all occurrences of elem
        in values have been removed
    """
    result = []
    
    for i in range(len(vals)):
        if vals[i] != elem:
            result += [vals[i]]
            
    return result

def get_pos_int(prompt):
    """ gets a positive integer from the user 
        based on the input string prompt.
        
        This problem lends itself to an indefinite loop
        because we don't know ahead of time how many
        repetitions we will need until the user enters
        a positive integer.
    """
    val = int(input(prompt))
    
    while val <= 0:
        val = int(input('The input must be positive. Try again: '))
        
    return val