Python 无法在单独的输出文件中使用for循环保存不同行中的数据

我试图将计算结果保存在输出文件中（使用python的open内置函数创建）。我的计算使用python中的for循环，我希望将所有结果保存在一个单独的输出文件中。但不幸的是，只有循环的最后一个值保存在输出文件中。为了让我的问题在下面更清楚，我正在分享我的代码

Nlayers = [2,3,4,5,6,7,8,9,10]

e_bulk = -33.071

TE2 = [-64.883,-97.954,-131.026,-164.097,-197.169,-230.240,-263.312,-296.383,-329.455]

area = 13.635


for i in range(len(Nlayers)):

        n = Nlayers[i]

        e_slab = TE2[i]

        sigma1 = (e_slab - (n*e_bulk)) / (2)

        sigma2 = (e_slab - (n*e_bulk)) / (2*area)

        fd = open('surf_energy', 'w')

        print('{0:3d} {1:13.2f} {2:15.4f}'. format(n, sigma1,sigma2),file=fd)

        fd.close()

在我的输出文件中，仅保存循环最后一个值的结果（即sigma1和sigma2的值）。但我想将所有结果保存在输出文件中。有人能帮我解决这个问题吗

Nlayers = [2,3,4,5,6,7,8,9,10]
e_bulk = -33.071
TE2 = [-64.883,-97.954,-131.026,-164.097,-197.169,-230.240,-263.312,-296.383,-329.455]
area = 13.635

with open("surf_energy", 'w') as my_file: # this ensures resources will be released after the block's scope ;
    for i in range(len(Nlayers)):
        n = Nlayers[i]
        e_slab = TE2[i]
        sigma1 = (e_slab - (n*e_bulk)) / (2)
        sigma2 = (e_slab - (n*e_bulk)) / (2*area)
        print('{0:3d} {1:13.2f} {2:15.4f}'. format(n, sigma1, sigma2), file = my_file)


# cat surf_energy

  2          0.63          0.0462
  3          0.63          0.0462
  4          0.63          0.0461
  5          0.63          0.0461
  6          0.63          0.0461
  7          0.63          0.0461
  8          0.63          0.0461
  9          0.63          0.0461
 10          0.63          0.0460