def write_lines(label, lines):
    '''write a list of lines with a header for a section.
    
       Parameters
       ==========
       lines: one or more lines to write, with header appended

    '''
    result = []
    continued = False
    for line in lines:
        if continued:
            result.append(line)
        else:
            result.append('%s %s' %(label, line))
        continued = False
        if line.endswith('\\'):
            continued = True
            
    return result
write a list of lines with a header for a section.
    
       Parameters
       ==========
       lines: one or more lines to write, with header appended