如何使用python从文本文件中提取特定行

Question

I have a text file having following content:

9.0 4.000000000001712e-05
8.996 0.009553763042602704
8.976 0.005684452508893222
8.96 -0.00353920143256147
8.956 -0.0044586273593916585
8.936 -0.012284767416576208
8.916 -0.019094598621809324
8.9 -0.020204776832571356

I have to extract each line starting with single point decimal number and write these numbers in a new file. like:

9.0 4.000000000001712e-05
8.9 -0.020204776832571356

Answer 1

以下正则表达式将起作用：

^\d*(?:\.\d{1,1})?\s

Answer 2

Try this:

with open('your_file.txt') as f:
    for line in f.readlines():
        vals = line.split(' ')
        if len(vals[0].split('.')[1]) == 1:
            print(line)