为什么这个子进程命令不起作用？

Question

我正在尝试删除多个 txt 文件的每一行中的第一个和最后一个逗号。当我运行以下脚本时，in_files 没有任何更改（即逗号仍然存在）。我错过了什么？有没有更好的方法来做到这一点？

我从this thread 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])

in_files (file1.txt)

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

预期

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

Answer 1

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")

这会将您的预期输出写入文件。