解析大型文本文档，仅保留“帐号”和特定的关键字（“市场价值”）

Question

我有一个大型文本文档（〜20000行），其正文看起来像这样：

Invoice Account / Name: 
0234523454 / XYZCORPORATIONS
Charge Group
Portfolio Fee
Date
Our / Your Ref
Security / Category
Charge Item
No of Units
Market Value
Charge Amt Invoice Amt
30-Sep-2019
Debt Instruments
PORTFOLIO FEE
CS
USD 
USD 219.12 USD 219.12
14,136,666.31
 Invoice Account / Name: 
021346676343/ abcdefgcopr
M0919-031  / Page 3 of 35
Charge Group
Portfolio Fee
Date
Our / Your Re
Security / Category
Charge Item
No of Units
Market Value
Charge Amt Invoice Amt
30-Sep-2019
Equity Instruments
USD 788,640.00 USD 12.22
USD 12.22
PORTFOLIO FEE-
EC_CS
 Invoice Account / Name: 
123498761233/ somethingelsecorporation
Charge Group
Portfolio Fee
Date
Our / Your Ref

这样的块重复了数千次。尝试输出：

Invoice Account / Name: 
    0234523454 / XYZCORPORATIONS
Market Value
Invoice Account / Name: 
    021346676343/ abcdefgcopr
Market Value
Invoice Account / Name: 
    123498761233/ somethingelsecorporation
Market Value

由于我以前从未尝试过类似的事情，所以我有两个问题：1.如何识别和保留这样的句子：

Invoice Account / Name: 
0234523454 / XYZCORPORATIONS

哪个没有固定长度？

1. 除此以外，如何仅保留关键字“市场价值”。

为此使用nltk是否明智？还是可以使用正则表达式和字符串处理来处理？

Answer 1

您可以仅使用字符串处理来搜索和查找所需内容。

result = []

with open('num.txt', 'r') as file:
    data = list(file.readlines())

    for indx, row in enumerate(data): 
        if 'Invoice Account' in row:

            accountnumber = data[indx+1].split('/')[0].strip() # Get account number from next line
            companyname = data[indx+1].split('/')[1].strip() # Get company name from next line

            # Store all results in a dictionary, you could print, store in other ways as well.

            info = {'Account Number': accountnumber,
                    'Company Name': companyname,
                    'Market Value': '',
                }

            # Append the dictionary to a list called result
            result.append(info)

然后您可以直接从每个词典访问数据，这些词典将仅包含各个公司的值。
for data in result:
    print(f"""Account Name: {data['Company Name']}
Account Number: {data['Account Number']}
Market Value: {data['Market Value']}
""")

输出：
Account Name: XYZCORPORATIONS
Account Number: 0234523454
Market Value: 

Account Name: abcdefgcopr
Account Number: 021346676343
Market Value: 

Account Name: somethingelsecorporation
Account Number: 123498761233
Market Value: