如何修复python3代码以从文本中提取特定行

Question

我试图从一个4.7gb的文本文件中提取特定的行到另一个文本文件中。你知道吗

我对python3.7.1还很陌生，这是我能想到的最好的代码。你知道吗

以下是文本文件的示例：

C00629618|N|TER|P|201701230300133512|15C|IND|DOE, JOHN A|PLEASANTVILLE|WA|00000|PRINCIPAL|DOUBLE NICKEL ADVISORS|01032017|40|H6CA34245|SA01251735122|1141239|||2012520171368850783
C00501197|N|M2|P|201702039042410893|15|IND|DOE, JANE|THE LODGE|GA|00000|UNUM|SVP, CORPORATE COMMUNICATIONS|01312017|230||PR1890575345050|1147350||P/R DEDUCTION ($115.00 BI-WEEKLY)|4020820171370029335
C00177436|N|M2|P|201702039042410893|15|IND|DOE, JOHN|RED ROOM|ME|00000|UNUM|SVP, DEPUTY GENERAL COUNSEL, BUSINESS|01312017|384||PR2260663445050|1147350||P/R DEDUCTION ($192.00 BI-WEEKLY)|4020820171370029336
C00177436|N|M2|P|201702039042410895|15|IND|PALMER, LAURA|TWIN PEAKS|WA|00000|UNUM|EVP, GLOBAL SERVICES|01312017|384||PR2283905245050|1147350||P/R DEDUCTION ($192.00 BI-WEEKLY)|4020820171370029342
C00501197|N|M2|P|201702039042410894|15|IND|COOPER, DALE|TWIN PEAKS|WA|00000|UNUM|SVP, CORP MKTG & PUBLIC RELAT.|01312017|384||PR2283904845050|1147350||P/R DEDUCTION ($192.00 BI-WEEKLY)|4020820171370029339

这是我写的代码：

import re

with open("data.txt", 'r') as rf:
    for line in rf:
        field_match = re.match('^(.*):(.*)$',line)

        if field_match :
            (key) = field_match.groups()
            if key == "C00501197" :
                print(rec.split('|'))

with open('extracted_data.txt','w') as wf:
    wf.write(line)

我需要提取包含id C00501197的完整行，然后让程序将这些提取的行写入另一个txt文件，但到目前为止，它只提取一行，而该行并不是以我要提取的id开头。你知道吗

Answer 1

您不需要通过regex，只需根据分隔符拆分行并检查您感兴趣的第n个字段：

found_lines = []

with open("data.txt", 'r') as rf:
    for line_file in rf:
        line = line_file.split("|")
        if line[0] == "C00501197" :
            found_lines.append( line )

with open('extracted_data.txt','w') as wf:
    for found_line in found_lines :
        wf.write("|".join(map(str,found_line)))

这应该管用。你知道吗