def indent_lines(fn_src, fn_dest):
    '''
    Sample 1: indent all lines of source file
    '''
    lines = read_file(fn_src)
    lines = map(lambda x: '    '+x, lines)
    write_file(fn_dest, lines)

    Sample 1: indent all lines of source file
    
recipes/Python/577199_File_readwrite_routines/recipe-577199.py