根据一天中的时间更改壁纸的Python脚本

Question

我正在用xfce运行Linux Mint 13。在this thread使用脚本，我能得到这个格式运行的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 

...但我遇到一些问题，剧本本身。由于是，改变什么，但目录名称，它给了我下面的错误：

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 

我试着调整了代码一点，它的排序工作;壁纸发生变化，但now.png最终被删除，导致cronjob运行时出现空白图像。这是我现在有：

#!/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") 

UPDATE：Blckknght的解决方案修复脚本。一切都很好，在薄荷13，但我已经升级到薄荷17.1，我再次遇到问题。该脚本工作得很好，但这一次，问题是与crontab。在这种运行每小时的cronjob结果：

Failed to parse arguments: Cannot open display: 

我改变了的cronjob这...

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

您当前的代码更复杂因为您正在重命名文件，因此需要将当前的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简单，覆盖该位置存在的现有文件。因为您正在复制而不是重命名，所以您永远不需要改变过程。

这里有一个版本的代码，这是否使用shutil.copy：。

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")