python - ftplib 结合 python 中的 os.unlink

Question

使用以下代码，我将 file.txt 上传到 ftp 服务器。文件上传后，我会在本地计算机上将其删除。

import os
from ftplib import FTP

HOST = 'host.com'
FTP_NAME = 'username'
FTP_PASS = 'password'
filepath = 'C:\file.txt'
while True:
    try:
        ftp = FTP(HOST)
        ftp.login(FTP_NAME, FTP_PASS)
        file = open(filepath, 'r')
        ftp.storlines('STOR file.txt', file)
        ftp.quit()
        file.close() # from this point on the file should not be in use anymore
        print 'File uploaded, now deleting...'
    except all_errors as e: #EDIT: Got exception here 'timed out'
        print 'error'       #      then the upload restarted.
        print str(e)

os.unlink(filepath) # now delete the file

代码有效，但有时(每 ~10 次上传)我收到此错误消息:

Traceback (most recent call last):
in os.unlink(filepath)
WindowsError: [Error 32] The process cannot access the file
because it is being usedby another process: 'C:\file.txt'

所以文件不能删除是因为“它还没有发布”之类的？我还尝试以这种方式取消链接文件:

while True: # try to delete the file until it is deleted...
    try:
        os.unlink(filepath)
        break
    except all_errors as e:
        print 'Cannot delete the File. Will try it again...'
        print str(e)

但是对于“try except block”，我也得到了同样的错误“该进程无法访问该文件，因为它正被另一个进程使用”!该脚本甚至没有尝试打印异常:

'Cannot delete the File. Will try it again...'

然后就停止了(如上)。

如何让 os.unlink 正常工作？谢谢!

Answer 1

import os
from ftplib import FTP

HOST = 'host.com'
FTP_NAME = 'username'
FTP_PASS = 'password'
filepath = 'C:\file.txt'
file = open(filepath, 'r')
while True:
    try:
        ftp = FTP(HOST)
        ftp.login(FTP_NAME, FTP_PASS)        
        ftp.storlines('STOR file.txt', file)
    except all_errors as e: #EDIT: Got exception here 'timed out'
        print 'error'       #      then the upload restarted.
        print str(e)
    else:
        ftp.quit()
        file.close() # from this point on the file should not be in use anymore
        print 'File uploaded, now deleting...'   
        os.unlink(filepath) # now delete the file
        break