@register.filter
def clear_list(list, clear=None):
    '''Template filters that clear list from unwanted elements, within django template. 
    
       Examples:
       
       l = [1, '1', '', ' ', None, 'www.abc.com']
       
       1)
       {{l|clear_list}} -> [1, '1', '', ' ','www.abc.com']
       
       2)
       {{l|clear_list:1}} -> ['1', '', ' ', None, 'www.abc.com']
       
       4)
       {{l|clear_list:'1'}} -> [1, '', ' ', None, 'www.abc.com']
       
       5)
       {{l|clear_list:''}} -> [1, '1', ' ', None, 'www.abc.com']
       
       6)
       {{l|clear_list:' '}} -> [1, '1', '', None, 'www.abc.com']
       
       7)
       {{l|clear_list:'www.abc.com'}} -> [ 1, '1', '', ' ', None]
       
       
       
       8)
       x = some_object(...)
       l = [1, 2, x]
       
       {{l|clear_list:x}} -> [1, 2]   
    '''
    
    try:
        return [i for i in list if i!=clear]
    except:
        return list