Question

我有这个python脚本

#!/usr/bin/env python
import datetime, os
from time import gmtime, strftime

to_backup = "/home/vmware/tobackup"
var1 = datetime.datetime.now().strftime('%b-%d-%I%p')
for f in os.listdir(to_backup):
    if(os.path.isfile(f)):
        print f + " is a file"
    if(os.path.isdir(f)):
        print f + " is a directory"

它给了我空的输出。我不知道问题出在哪里

输出jimbob博士回答

total 36
-rwxrwxr-x 1 vmware vmware  440 May  5 07:41 back.py
-rwxrwxr-x 1 vmware vmware 2624 May  4 20:35 backup.sh
drwxr-xr-x 2 vmware vmware 4096 Jun 22  2010 Desktop
drwxrwxr-x 2 vmware vmware 4096 May  5 03:51 destination
drwxr-xr-x 2 root   root   4096 May  4 18:49 public_html
drwxrwxr-x 2 vmware vmware 4096 May  1 07:47 python
-rwxrwxr-x 1 vmware vmware  560 May  1 13:20 regex.py
drwxrwxrwx 7 vmware vmware 4096 May  5 03:50 tobackup
total 20
drwxrwxrwx 2 vmware vmware 4096 May  5 03:50 five
drwxrwxrwx 2 vmware vmware 4096 May  5 03:50 four
drwxrwxrwx 2 vmware vmware 4096 May  5 03:50 one
drwxrwxrwx 2 vmware vmware 4096 May  5 03:50 three
drwxrwxrwx 2 vmware vmware 4096 May  5 03:50 two

Answer 1

好的，您有权限，但在列出文件时，您不在正确的目录中。 list_dir为您提供没有路径的目录/文件列表，os.path.isfile('one')和os.path.isdir('one')将检查当前目录中是否存在目录“one”（无论您何时从中启动脚本，除非您明确更改）目录os.chdir或包含路径，例如os.path.isdir('/home/vmware/tobackup/one')。

#!/usr/bin/env python
import datetime, os
from time import gmtime, strftime
import subprocess

to_backup = "/home/vmware/tobackup"
var1 = datetime.datetime.now().strftime('%b-%d-%I%p')

os.chdir(to_backup)
# os.listdir(to_backup) = ['one', 'two', 'three', 'four', 'five']
for f in os.listdir(to_backup):
    if(os.path.isfile(f)):
        print f + " is a file"
    if(os.path.isdir(f)):
        print f + " is a directory"

或

to_backup = "/home/vmware/tobackup"
var1 = datetime.datetime.now().strftime('%b-%d-%I%p')
# os.listdir(to_backup) = ['one', 'two', 'three', 'four', 'five']
for f in os.listdir(to_backup):
    if(os.path.isfile(os.path.join(to_backup,f))):
        print f + " is a file"
    if(os.path.isdir(os.path.join(to_backup,f))):
        print f + " is a directory"

或walk（但实际上没有穿过子目录）。

to_backup = "/home/vmware/tobackup"
var1 = datetime.datetime.now().strftime('%b-%d-%I%p')

root, dirs, files in os.walk(to_backup).next()
for file in files:
    print f + " is a file in " + root
for dir in dirs:
    print f + " is a directory"

编辑：为了更清楚，原始脚本的错误是你有一个文件结构：

/home/user/bin/your_script.py
/home/vmware/tobackup/
/home/vmware/tobackup/one
/home/vmware/tobackup/two
...

当您转到/ home / user / bin运行脚本（例如python your_script.py）时，os.listdir('/home/vmware/tobackup')会在/ home / vmware / tobackup中为您提供文件和目录名称列表，是['one','two', ...]。但是，当您从目录/ home / user / bin执行os.path.isfile('one')时，检查/home/user/bin/one是否为文件，而不是/ home / vmware / tobackup / one是否为文件。由于/home/user/bin/one不存在，因此无法输出。

Answer 2

它适用于我的机器（ubuntu 10.10）也许/ home / vmware / tobackup是空的，或者你没有权限阅读它。

Answer 3

os.listdir(dir_name)返回相对于指定目录的文件名。要在其他命令中使用它们，您需要预先添加目录名称（在循环体的开头通过f = os.path.join(to_backup, f)），或者在开始循环之前将工作目录更改为备份目录。

这是jimbob博士回答中显示的前两个替代方案。

Python脚本无法在linux中运行

3 个答案: