def make_pairs(txt):
    
    """
    Takes a string ('txt') and separates it into 
    pairs of characters returning a list with those pairs.
    """
    
    lista = []
    string = ""  
    count = 0
    
    if len(txt)%2 != 0 :
        count = 1
    
    for i in range(len(txt)):
        
        string += txt[i]
        count += 1
        
        if count == 2:
            lista.append(string)
            string = ""
            count = 0
        
    return lista