试图从一个目录中的许多文本文件中复制一组特定的字符串并将它们粘贴到一个新的文本文件中

Question

I am pretty new to python and I am trying to sort through a directory's files that start with 'O0' and copy any string in the text files that has an 'F', 'T', or 'S' in them, and paste, preferably just that string, (but the whole line would still work) in a new text file, preferably on the desktop. It is making the text file, but it is blank, and python does not close the file. Here's what I have so far:

import os

 # definitions
 directory = (r'\directoryname')
 feedsspeeds = open('feedsspeeds.txt', 'a+')


 # scanning through sub folders
 for file in os.scandir(directory):
    if file.path.startswith("O0"):
        with open(file, 'r') as f:
                for line in file:
                    if ('F', 'T', 'S') in line:
                            feedsspeeds.append(line)
                                   

Answer 1

In the first place you are probably getting an AttributeError error that append is not known. Because you try to append your text to the TextIOwrapper ( feeds speeds ). You have to use the write method to append the text to the file content.

Also note that your file is read and written from the current directory, so ./feedsspeeds.txt . As long as you are not executing this script from you Desktop folder, the file will also not be written there.

Answer 2

Your problem is with for line in file: . You want to loop on f , not file .

As a side note I can foresee a problem with if ('F', 'T', 'S') in line: . The in operator on a string requires a string as left operand. You are providing a tuple.

What you want to do is if 'F' in line or 'T' in line or 'S' in line: .

Bonus: filtering to output only relevants parts

Warning: untested code

for file in os.scandir(directory):
    if file.path.startswith("O0"):
        with open(file, 'r') as f:
                for line in f:
                    for item in line.split(): # by default split() use space as separator
                        if 'F' in item or 'T' in item or 'S' in item:
                            feedsspeeds.append(item)