使用Python解析文本文件并将数字保存在数组中并在csv中导出

Question

我想在python 2.7中解析一些文本并将结果导出到数组中。 例如，

Record # 3741: 2018 Feb 16  13:26:27.632  [00] abc adbada adba adab adbadba bdadba 
 =>  abc_cdf_ghk_adha 468 H S16.7:Output [0] 0 [1] 0 [2] 0 [3] 0 
   Record # 3742: 2018 Feb 16  13:26:27.632  [00] abc adbada adba adab adbadba bdadba 
 =>  abc_cdf_ghk_adha 474 H S16.7:Output [4] 0 [5] 0 [6] 0 [7] 0 [8] 0 
   Record # 3795: 2018 Feb 16  13:26:27.633  [00] abc adbada adba adab adbadba bdadba 
 =>  abc_cdf_ghk_adha 468 H S16.7:Output [0] 16861 [1] 16867 [2] 16873 [3] 16878 
   Record # 3800: 2018 Feb 16  13:26:27.633  [00] abc adbada adba adab adbadba bdadba 
 =>  abc_cdf_ghk_adha 474 H S16.7:Output [4] 16873 [5] 16861 [6] 0 [7] 0 [8] 0 
   Record # 3931: 2018 Feb 16  13:26:27.634  [00] abc adbada adba adab adbadba bdadba 
 =>  abc_cdf_ghk_adha 468 H S16.7:Output [0] 16873 [1] 16867 [2] 128 [3] 128 
   Record # 3932: 2018 Feb 16  13:26:27.634  [00] abc adbada adba adab adbadba bdadba 
 =>  abc_cdf_ghk_adha 474 H S16.7:Output [4] 16878 [5] 16873 [6] 16855 [7] 16867 [8] 16873 
   Record # 3971: 2018 Feb 16  13:26:27.635  [00] abc adbada adba adab adbadba bdadba 
 =>  abc_cdf_ghk_adha 468 H S16.7:Output [0] 16855 [1] 16849 [2] 129 [3] 129 
   Record # 3974: 2018 Feb 16  13:26:27.635  [00] abc adbada adba adab adbadba bdadba 
 =>  abc_cdf_ghk_adha 474 H S16.7:Output [4] 16867 [5] 16867 [6] 16861 [7] 16861 [8] 16867

从这些特定的行中，我想解析偶数行并将数字保存在数组中。 我应该有9个数组（A0，A1，A2，A3，... A8），并不断更新数组。

在上述情况下，A0应该是[0]之后的值

Variables: 
A0 --> [0] numbers after [0]
A1 --> [1] numbers after [1]
A2 --> [2] numbers after [2]
A3 --> [3] numbers after [3]
A4 --> [4] numbers after [4]
A5 --> [5] numbers after [5]
A6 --> [6] numbers after [6]
A7 --> [7] numbers after [7]
A8 --> [8] numbers after [8]

在此循环结束时，我会将变量保存在一个csv文件中。

我使用python的方法是这样的：

import re
from collections import defaultdict
import numpy as np
import matplotlib.pyplot as plt

result = defaultdict(list)
with open("C:\\Users\\ibrah\\Documents\\Python\\Test\\Input.txt","r") as f:
    for c, l in enumerate(f.readlines()): # Get enumerate to keep track of line numbers
        if (c+1) % 2 == 0: # Even lines (line numbers start at 0)
            for m in re.findall('(?:\[(\d+)\])\s(\d+)', l): # 1st regex group will the the number in the []s and 2nd group will be the number after
                result[int(m[0])].append(int(m[1]))
RS0 = 10*(np.log10(result[0]/128))
RS1 = 10*(np.log10(result[1]/128))
RS2 = 10*(np.log10(result[2]/128))
RS3 = 10*(np.log10(result[3]/128))
RS4 = 10*(np.log10(result[4]/128))
RS5 = 10*(np.log10(result[5]/128))
RS6 = 10*(np.log10(result[6]/128))
RS7 = 10*(np.log10(result[7]/128))
RS8 = 10*(np.log10(result[8]/128))
plt.plot([RS0,RS1,RS2,RS3,RS4,RS5,RS6,RS7,RS8])
#plt.plot([RS0])
plt.ylabel('SNR')
plt.show()

**在这里，我试图绘制变量（RS0 ... RS8），并将值导出到csv文件。 请您协助我完成代码以执行此操作。

Answer 1

您可以使用更好的正则表达式来捕获所有出现的[X] Y 将其与with子句， enumerate()和defaultdict(list)以保持代码更整洁，您将获得如下内容：

import re
from collections import defaultdict

result = defaultdict(list)
with open('C:\Users\xxxx\Contents.txt', 'r') as f:
    for c, l in enumerate(f.readlines()): # Get enumerate to keep track of line numbers
        if (c+1) % 2 == 0: # Even lines (line numbers start at 0)
            for m in re.findall('(?:\[(\d+)\])\s(\d+)', l): # 1st regex group will the the number in the []s and 2nd group will be the number after
                result[int(m[0])].append(int(m[1]))

A0 = result[0]
A1 = result[1]
# ...

如果之后要绘制结果数组，请首先确保首先通过np.array(result[0])将Python列表转换为numpy数组。 否则，您将获得：

TypeError：/：'list'和'int'不支持的操作数类型

然后，确保在处理对数之前以某种方式处理数组中的0，因为log(0)是未定义的。 您可以尝试将1加到这些值，然后取它们的日志。

最后，您不需要创建所有这些变量-列表理解将更优雅地工作：

plt.plot([10*np.log10(np.array(result[i])/128) for i in sorted(result.keys())])

Answer 2

如果对于以=>开头的每一行，您希望将Output之后的数字作为int列表，则可以执行以下操作：

import re

with open('file.txt') as f:
    lines = [l for l in f.readlines() if l.startswith('=>')]

parsed_lines = []
for line in lines:
    numbers = re.findall('\d+', line.split('Output')[1])
    parsed_lines.append([int(e) for e in numbers])

print(parsed_lines)

因此，对于给定的文件，您将拥有：

[
    [0, 0, 1, 0, 2, 0, 3, 0],
    [4, 0, 5, 0, 6, 0, 7, 0, 8, 0],
    [0, 16861, 1, 16867, 2, 16873, 3, 16878],
    [4, 16873, 5, 16861, 6, 0, 7, 0, 8, 0],
    [0, 16873, 1, 16867, 2, 128, 3, 128],
    [4, 16878, 5, 16873, 6, 16855, 7, 16867, 8, 16873],
    [0, 16855, 1, 16849, 2, 129, 3, 129],
    [4, 16867, 5, 16867, 6, 16861, 7, 16861, 8, 16867]
]