使用Python更改文本文件中的特定列值

我有一个文本文件，如下所示：

1  1  2  1  1e8
2  1  2  3  1e5
3  2  3  2  2000
4  2  5  6  1000
5  2  4  3  1e4
6  3  6  4  5000
7  3  5  2  2000
8  3  2  3  5000
9  3  4  5  1e9
10 3  2  3  1e6

我的问题是如何更改一列（例如，将最后一列中的所有数据除以900）并将整个数据保存在新文件中？

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提前感谢您的每一行文件

    vals = line.split(' ')
    my_val = float(vals[4])/900
    output  = open('filename', 'wb')
    output.write(my_val +'\n')

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您可以使用numpy库。下面的代码应该可以做到这一点

import numpy as np

# assume the data is in.txt file
dat = np.loadtxt('in.txt')

# -1 means the last column
dat[:, -1] = dat[:, -1]/900

# write the result to the out.txt file
# fmt is the format while writing to the file
# %.2f means that it will save it to the 2 digits precision
np.savetxt('out.txt', dat, fmt='%.2f')

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使用简单的迭代

res = []
with open(filename, "r") as infile:
    for line in infile:                        # Iterate each line 
        val = line.split()                     # Split line by space
        res.append( str(float(val[-1])/900) )  # Use negative index to get last element and divide.

with open(filename, "w") as outfile:          #Open file to write
    for line in res:
        outfile.write(line+"\n")              #Write Data

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请把你的密码寄出去