Python 3.x 为什么此子流程命令不起作用？

我试图删除多个

txt

文件中每行的第一个和最后一个逗号。当我运行下面的脚本时，_文件中的

都没有更改（即逗号仍然存在）。我错过了什么？有更好的方法吗

我从中找到了
rev
命令

我的脚本

import subprocess
from glob import glob

in_files = glob('path/to/files/*.txt')

for fyle in in_files:
    rr = f"rev {fyle} | cut -c2- | rev | cut -c2-"
    subprocess.check_output(['bash', '-c', rr])

,-0.12000000000000000,0.0000000000000000,
,-0.11889999999999999,0.0000000000000000,
,-0.11780000000000000,0.0000000000000000,
,-0.11670000000000000,0.0000000000000000,
,-0.11559999999999999,0.0000000000000000,
,-0.11449999999999999,0.0000000000000000,

文件（file1.txt）

预期的

-0.12000000000000000,0.0000000000000000
-0.11889999999999999,0.0000000000000000
-0.11780000000000000,0.0000000000000000
-0.11670000000000000,0.0000000000000000
-0.11559999999999999,0.0000000000000000
-0.11449999999999999,0.0000000000000000

您是否需要使用外部程序，或者这是否适合您的需要

def trim(filename, new_filename):
    with open(filename) as infile:
        with open(new_filename, "w") as outfile:
            for line in infile:
                outfile.write(line.strip(",\n") + "\n")

file_list = ["file1.txt"]
for f in file_list:
    # btw if you want the original file to
    # be overwritten, call `trim(f, f)`
    trim(f, f+"_new.txt")

这会将您预期的输出写入文件。
为什么这会被否决？这很有效，谢谢，但我仍然想知道为什么我的subprocess命令不起作用。