你可以用对齐的格式添加。＃f 。

You can just add the .#f in the format with the alignment.

with open('format_test.dat', "a") as f_out:
    f_out.write('''{:>10.2f} {:>15.4f} {:>16.5f} {:>15.3f}'''.format(a, b, c, d))
    f_out.write('\n')