我对python还是个新手，我知道我的代码看起来很难看。我有忽略错误的问题（traceback）并继续执行命令。下面的代码检查文件是否存在（使用ftp.size）并打印消息，如果是的话。这里有一个问题。当它在这个主目录中找不到文件时，它应该转到/folder 2并在这里查找文件。相反，它抛出了回溯错误（我将其“静音”），并且没有转到第二个文件夹...

from ftplib import FTP
import sys
sys.tracebacklimit = 0

ftp = FTP(host="ip")
loginRepsonse = ftp.login(user='name', passwd='password')
print(loginRepsonse)

fileName = "2022121414040114FTPtestLarge.txt"
# fileName = str(input('What is name of your file? '))

size = ftp.size(fileName)

if isinstance(size, int):
    print("File exists!")
else :    
    ftp.cwd('/folder2')
    if isinstance(size, int):
        print("File exists in another directory!")

while True:
   pass

当文件存在时，这一切都很酷，它表明文件确实存在，但当不存在时...下面的错误出现，执行结束，而不看第二个文件夹...

ftplib.error_perm: 550 Could not get file size.

请注意这个

while True:
   pass

只是为了让我的脚本（在cmd中）保持活跃，不要在写入名称之前随机关闭输入😁我的FTP只有“主”目录和一个子文件夹-代码需要检查两个文件夹（主，然后第二个文件夹，如果文件没有找到）.如何忽略这个错误并继续搜索？
下面是整个错误输出与不存在的文件（同样的情况发生在现有的文件，但在不同的目录，我无法访问）：

230 Login successful.
Traceback (most recent call last):
  File "c:\Users\user\Desktop\CODES+SCRIPTS\ftp.py", line 13, in <module>
    size = ftp.size(fileName)
           ^^^^^^^^^^^^^^^^^^
  File "C:\Users\user\AppData\Local\Programs\Python\Python311\Lib\ftplib.py", line 630, in size
    resp = self.sendcmd('SIZE ' + filename)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\user\AppData\Local\Programs\Python\Python311\Lib\ftplib.py", line 281, in sendcmd
    return self.getresp()
           ^^^^^^^^^^^^^^
  File "C:\Users\user\AppData\Local\Programs\Python\Python311\Lib\ftplib.py", line 254, in getresp
    raise error_perm(resp)
ftplib.error_perm: 550 Could not get file size.

下面是我尝试的另一个代码：

from ftplib import FTP

ftp = FTP(host="ip")
loginRepsonse = ftp.login(user='user', passwd='pass')
print(loginRepsonse)

fileName = "2022121608003014FTPtest.txt"   #this file exists in 2nd folder

size = ftp.size(fileName)

from ftplib import FTP, error_perm
try:
    size = ftp.size(fileName)
    print(f"File exists {size}")
    ftp.cwd('/test')          #checks subfolder(or it should..)
    if isinstance(size, int):
         print("File exists in another directory!")
except error_perm as e:
    print(f"File does not exist anywhere: {e}")

以下是工作（未完成）代码：

from ftplib import FTP
from ftplib import FTP, error_perm

ftp = FTP(host="68.183.3.24")
loginRepsonse = ftp.login(user='sumeyra', passwd='Pysense2020!')
print(loginRepsonse)

def repeat():
    fileName = str(input('>>> What is name of your file? \n'))
    try:
        size = ftp.size(fileName)
        print(f"File exists in main directory.")
    except error_perm as e:
        pass
        print(f"File does not exist in main directory.")

    try:
        ftp.cwd('/testLAB')
        size = ftp.size(fileName)
        if isinstance(size, int):
                print("File exists in subfolder!")
    except:
        print(f"File does not exist anywhere yet.")

while True:
   repeat()