python - 子进程 python filenotfounderror : [winerror 2]

Question

我一直在使用 Jupyter Notebook 来学习 Principal Component Analysis from kaggle ), 但是当我运行这段代码时

     from subprocess import check_output
     print(check_output(["ls", "../input"]).decode("utf8"))

下面有错误

FileNotFoundError Traceback (most recent call last)
<ipython-input-3-de0e39ca3ab8> in <module>()
      1 from subprocess import check_output
----> 2 print(check_output(["ls", "C:/Users/wanglei/Documents/input"]).decode("utf8"))

D:\Anaconda3\lib\subprocess.py in check_output(timeout, *popenargs, **kwargs)
    624 
    625     return run(*popenargs, stdout=PIPE, timeout=timeout, check=True,
--> 626                **kwargs).stdout
    627 
    628 

D:\Anaconda3\lib\subprocess.py in run(input, timeout, check, *popenargs, **kwargs)
    691         kwargs['stdin'] = PIPE
    692 
--> 693     with Popen(*popenargs, **kwargs) as process:
    694         try:
    695             stdout, stderr = process.communicate(input, timeout=timeout)

D:\Anaconda3\lib\subprocess.py in __init__(self, args, bufsize, executable, stdin, stdout, stderr, preexec_fn, close_fds, shell, cwd, env, universal_newlines, startupinfo, creationflags, restore_signals, start_new_session, pass_fds)
    945                                 c2pread, c2pwrite,
    946                                 errread, errwrite,
--> 947                                 restore_signals, start_new_session)
    948         except:
    949             # Cleanup if the child failed starting.

D:\Anaconda3\lib\subprocess.py in _execute_child(self, args, executable, preexec_fn, close_fds, pass_fds, cwd, env, startupinfo, creationflags, shell, p2cread, p2cwrite, c2pread, c2pwrite, errread, errwrite, unused_restore_signals, unused_start_new_session)
   1222                                          env,
   1223                                          cwd,
-> 1224                                          startupinfo)
   1225             finally:
   1226                 # Child is launched. Close the parent's copy of those pipe

路径是正确的，似乎所有来自子进程的调用都会类似地失败。

有人知道为什么会这样吗？

Answer 1

此代码运行 ls command ，这is available on all POSIX-conforming systems .

您正在使用 Microsoft Windows。默认情况下，Microsoft Windows 不符合 POSIX。例如，没有 ls 二进制文件。因此，子进程找不到文件 ls，从而发出 FileNotFoundError。

您可以安装Microsoft's Bash on Windows ，这会给你 ls。

但是，pythonic 和更便携的列出目录的方法首先不是使用子进程，而是内置的 os.listdir :

import os
print(os.listdir('../input'))