Question

我用xfce运行Linux Mint 13。使用this thread中的脚本，我能够以这种格式运行cronjob：

PATH=/usr/bin/python/:/usr/bin/python3/:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin

# The Wallpaper Changer
0 * * * * /home/tessitura/8BitDay/set.py

...但是我遇到了脚本本身的一些问题。原样，只更改目录名称，它给我以下错误：

Traceback (most recent call last):
  File "./set.py", line 19, in <module>
    os.rename('now.png', current)    
OSError: [Errno 2] No such file or directory

我尝试过稍微调整一下代码，这有点起作用;壁纸更改，但 now.png 最终被删除，导致cronjob运行时出现空白图像。这就是我现在所拥有的：

#!/usr/bin/python3    

# Finds the current hour
import datetime
time = int(str(datetime.datetime.now().time()).split(":")[0])    

# Needed for renaming files
import os    

# List of all files in the folder
files = ['05-Evening.png', 'set.py', '07-Night.png', '01-Morning.png', '03-Afternoon.png', '06-Late-Evening.png', '08-Late-Night.png', '04-Late-Afternoon.png', '02-Late-Morning.png', 'now.png']   

# Finds which wallpaper is currently set
directory = "/home/tessitura/8BitDay/"
for filename in os.listdir(directory):
    files.remove(files[files.index(filename)])
    current = ''.join(filename)    

# Puts back the current wallpaper
path = os.path.join(directory, 'now.png')
os.rename(path, current)    

# Gets out the new wallpaper based on time
if 0 <= time <= 3:
    os.rename('08-Late-Night.png', 'now.png')
elif 4 <= time <= 5:
    os.rename('01-Morning.png', 'now.png')
elif 6 <= time <= 10:
    os.rename('02-Late-Morning.png', 'now.png')
elif 11 <= time <= 14:
    os.rename('03-Afternoon.png', 'now.png')
elif 15 <= time <= 16:
    os.rename('04-Late-Afternoon.png', 'now.png')
elif 17 <= time <= 18:
    os.rename('06-Late-Evening.png', 'now.png')
elif 19 <= time <= 23:
    os.rename('07-Night.png', 'now.png')    

# Refreshes the desktop
os.system("xfdesktop --reload")

更新：Blckknght的解决方案修复了该脚本。 Mint 13中的一切都很好，但是我已经升级到Mint 17.1，我又遇到了问题。该脚本可以很好地独立运行，但这一次，问题在于crontab。运行每小时的cronjob导致：

Failed to parse arguments: Cannot open display:

我把cronjob改成了这个......

PATH=/usr/bin/python/:/usr/bin/python3/:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
@hourly DISPLAY=:0.0 /home/tessitura/8BitDay/set.py > /home/tessitura/set.log 2>&1

这给了我这个错误：

Failed to connect to session manager: Failed to connect to the session manager: SESSION_MANAGER environment variable not defined

** (xfdesktop:9739): WARNING **: xfdesktop: already running, quitting.

Answer 1

您当前的代码比您需要的更复杂，因为您正在重命名文件，因此需要将当前now.png文件重命名为其原始名称。

将适合时间的文件复制到新名称会更加简单，如果存在，则覆盖该位置的现有文件。因为您正在复制而不是重命名，所以您永远不需要反转该过程。

以下是使用shutil.copy执行此操作的代码版本：

import datetime
import os
import shutil

time = datetime.datetime.now().hour  # no need for string parsing to get the hour

# Gets out the new wallpaper based on time
if 0 <= time <= 3:
    shutil.copy('08-Late-Night.png', 'now.png')
elif 4 <= time <= 5:
    shutil.copy('01-Morning.png', 'now.png')
elif 6 <= time <= 10:
    shutil.copy('02-Late-Morning.png', 'now.png')
elif 11 <= time <= 14:
    shutil.copy('03-Afternoon.png', 'now.png')
elif 15 <= time <= 16:
    shutil.copy('04-Late-Afternoon.png', 'now.png')
elif 17 <= time <= 18:
    shutil.copy('06-Late-Evening.png', 'now.png')
elif 19 <= time <= 23:
    shutil.copy('07-Night.png', 'now.png')    

# Refreshes the desktop
os.system("xfdesktop --reload")

Python脚本根据时间更改壁纸

1 个答案: