我对Ubuntu / Python / Bash / Gnome一般都是新手，所以我仍然觉得我有可能做错了什么，但现在已经3天没有成功......
以下是剧本应该做的事情：
* [✓]从wallbase.cc下载1张随机图像
* [✓]将其保存到运行脚本的同一目录中
* [x]将其设置为壁纸
有两次尝试使用不同的命令设置壁纸两个，并且在脚本中NEITHER工作。有一个打印声明（从底部开始的第二行）吐出正确的终端命令，因为我可以C＆amp; P打印结果并且它工作正常，它只是在脚本中执行时不起作用。
#!/usr/bin/env python
import urllib2
import os
from gi.repository import Gio
response = urllib2.urlopen("http://wallbase.cc/random/12/eqeq/1366x768/0.000/100/32")
page_source = response.read()
thlink_pos = page_source.find("ico-X")
address_start = (page_source.find("href=\"", thlink_pos) + 6)
address_end = page_source.find("\"", address_start + 1)
response = urllib2.urlopen(page_source[address_start:address_end])
page_source = response.read()
bigwall_pos = page_source.find("bigwall")
address_start = (page_source.find("src=\"", bigwall_pos) + 5)
address_end = page_source.find("\"", address_start + 1)
address = page_source[address_start:address_end]
slash_pos = address.rfind("/") + 1
pic_name = address[slash_pos:]
bashCommand = "wget " + page_source[address_start:address_end]
os.system(bashCommand)
print "Does my new image exists?", os.path.exists(os.getcwd() + "/" + pic_name)
#attempt 1
settings = Gio.Settings.new("org.gnome.desktop.background")
settings.set_string("picture-uri", "file://" + os.getcwd() + "/" + pic_name)
settings.apply()
#attempt 2
bashCommand = "gsettings set org.gnome.desktop.background picture-uri file://" + os.getcwd() + "/" + pic_name
print bashCommand
os.system(bashCommand)
settings.apply()
答案 0 :(得分：2)
您已成功更改了设置，但仍然未应用，请尝试下一步：
settings.apply()
设置“picture-uri”字符串后。
答案 1 :(得分：0)
它对我有用（Ubuntu 12.04）。
我修改了你的脚本（与你的错误无关）：
#!/usr/bin/python
"""Set desktop background using random images from http://wallbase.cc
It uses `gi.repository.Gio.Settings` to set the background.
"""
import functools
import itertools
import logging
import os
import posixpath
import random
import re
import sys
import time
import urllib
import urllib2
import urlparse
from collections import namedtuple
from bs4 import BeautifulSoup # $ sudo apt-get install python-bs4
from gi.repository.Gio import Settings # pylint: disable=F0401,E0611
DEFAULT_IMAGE_DIR = os.path.expanduser('~/Pictures/backgrounds')
HTMLPAGE_SIZE_MAX = 1 << 20 # bytes
TIMEOUT_MIN = 300 # seconds
TIMEOUT_DELTA = 30 # jitter
# "Anime/Manga", "Wallpapers/General", "High Resolution Images"
CATEGORY_W, CATEGORY_WG, CATEGORY_HR = range(1, 4)
PURITY_SFW, PURITY_SKETCHY, PURITY_NSFW, PURITY_DEFAULT = 4, 2, 1, 0
DAY_IN_SECONDS = 86400
UrlRetreiveResult = namedtuple('UrlRetreiveResult', "path headers")
def set_background(image_path, check_exist=True):
"""Change desktop background to image pointed by `image_path`.
"""
if check_exist: # make sure we can read it (at this time)
with open(image_path, 'rb') as f:
f.read(1)
# prepare uri
path = os.path.abspath(image_path)
if isinstance(path, unicode): # quote() doesn't like unicode
path = path.encode('utf-8')
uri = 'file://' + urllib.quote(path)
# change background
bg_setting = Settings.new('org.gnome.desktop.background')
bg_setting.set_string('picture-uri', uri)
bg_setting.apply()
def url2filename(url):
"""Return basename corresponding to url.
>>> url2filename('http://example.com/path/to/file?opt=1')
'file'
"""
urlpath = urlparse.urlsplit(url).path # pylint: disable=E1103
basename = posixpath.basename(urllib.unquote(urlpath))
if os.path.basename(basename) != basename:
raise ValueError # refuse 'dir%5Cbasename.ext' on Windows
return basename
def download(url, dirpath, extensions=True, filename=None):
"""Download url to dirpath.
Use basename of the url path as a filename.
Create destination directory if necessary.
Use `extensions` to require the file to have an extension or any
of in a given sequence of extensions.
Return (path, headers) on success.
Don't retrieve url if path exists (headers are None in this case).
"""
if not os.path.isdir(dirpath):
os.makedirs(dirpath)
logging.info('created directory %s', dirpath)
# get filename from the url
filename = url2filename(url) if filename is None else filename
if os.path.basename(filename) != filename:
logging.critical('filename must not have path separator in it "%s"',
filename)
return
if extensions:
# require the file to have an extension
root, ext = os.path.splitext(filename)
if root and len(ext) > 1:
# require the extension to be in the list
try:
it = iter(extensions)
except TypeError:
pass
else:
if ext not in it:
logging.warn(("file extension is not in the list"
" url=%s"
" extensions=%s"),
url, extensions)
return
else:
logging.warn("file has no extension url=%s", url)
return
# download file
path = os.path.join(dirpath, filename)
logging.info("%s\n%s", url, path)
if os.path.exists(path): # don't retrieve if path exists
logging.info('path exists')
return UrlRetreiveResult(path, None)
try:
return UrlRetreiveResult(*urllib.urlretrieve(url, path,
_print_download_status))
except IOError:
logging.warn('failed to download {url} -> {path}'.format(
url=url, path=path))
def _print_download_status(block_count, block_size, total_size):
logging.debug('%10s bytes of %s', block_count * block_size, total_size)
def min_time_between_calls(min_delay):
"""Enforce minimum time delay between calls."""
def decorator(func):
lastcall = [None] # emulate nonlocal keyword
@functools.wraps(func)
def wrapper(*args, **kwargs):
if lastcall[0] is not None:
delay = time.time() - lastcall[0]
if delay < min_delay:
_sleep(min_delay - delay)
lastcall[0] = time.time()
return func(*args, **kwargs)
return wrapper
return decorator
@min_time_between_calls(5)
def _makesoup(url):
try:
logging.info(vars(url) if isinstance(url, urllib2.Request) else url)
page = urllib2.urlopen(url)
soup = BeautifulSoup(page.read(HTMLPAGE_SIZE_MAX))
return soup
except (IOError, OSError) as e:
logging.warn('failed to return soup for %s, error: %s',
getattr(url, 'get_full_url', lambda: url)(), e)
class WallbaseImages:
"""Given parameters it provides image urls to download."""
def __init__(self,
categories=None, # default; sequence of CATEGORY_*
resolution_exactly=True, # False means 'at least'
resolution=None, # all; (width, height)
aspect_ratios=None, # all; sequence eg, [(5,4),(16,9)]
purity=PURITY_DEFAULT, # combine with |
thumbs_per_page=None, # default; an integer
):
"""See usage below."""
self.categories = categories
self.resolution_exactly = resolution_exactly
self.resolution = resolution
self.aspect_ratios = aspect_ratios
self.purity = purity
self.thumbs_per_page = thumbs_per_page
def _as_request(self):
"""Create a urllib2.Request() using given parameters."""
# make url
if self.categories is not None:
categories = "".join(str(n) for n in (2, 1, 3)
if n in self.categories)
else: # default
categories = "0"
if self.resolution_exactly:
at_least_or_exactly_resolution = "eqeq"
else:
at_least_or_exactly_resolution = "gteq"
if self.resolution is not None:
resolution = "{width:d}x{height:d}".format(
width=self.resolution[0], height=self.resolution[1])
else:
resolution = "0x0"
if self.aspect_ratios is not None:
aspect_ratios = "+".join("%.2f" % (w / float(h),)
for w, h in self.aspect_ratios)
else: # default
aspect_ratios = "0"
purity = "{0:03b}".format(self.purity)
thumbs = 20 if self.thumbs_per_page is None else self.thumbs_per_page
url = ("http://wallbase.cc/random/"
"{categories}/"
"{at_least_or_exactly_resolution}/{resolution}/"
"{aspect_ratios}/"
"{purity}/{thumbs:d}").format(**locals())
logging.info(url)
# make post data
data = urllib.urlencode(dict(query='', board=categories, nsfw=purity,
res=resolution,
res_opt=at_least_or_exactly_resolution,
aspect=aspect_ratios,
thpp=thumbs))
req = urllib2.Request(url, data)
return req
def __iter__(self):
"""Yield background image urls."""
# find links to bigwall pages
# css-like: #thumbs div[class="thumb"] \
# a[class~="thlink" and href^="http://"]
soup = _makesoup(self._as_request())
if not soup:
logging.warn("can't retrieve the main page")
return
thumbs_soup = soup.find(id="thumbs")
for thumb in thumbs_soup.find_all('div', {'class': "thumb"}):
bigwall_a = thumb.find('a', {'class': "thlink",
'href': re.compile(r"^http://")})
if bigwall_a is None:
logging.warn("can't find thlink link")
continue # try the next thumb
# find image url on the bigwall page
# css-like: #bigwall > img[alt and src^="http://"]
bigwall_soup = _makesoup(bigwall_a['href'])
if bigwall_soup is not None:
bigwall = bigwall_soup.find(id='bigwall')
if bigwall is not None:
img = bigwall.find('img',
src=re.compile(r"(?i)^http://.*\.jpg$"),
alt=True)
if img is not None:
url = img['src']
filename = url2filename(url)
if filename.lower().endswith('.jpg'):
yield url, filename # successfully found image url
else:
logging.warn('suspicious url "%s"', url)
continue
logging.warn("can't parse bigwall page")
def main():
level = logging.INFO
if '-d' in sys.argv:
sys.argv.remove('-d')
level = logging.DEBUG
# configure logging
logging.basicConfig(format='%(levelname)s: %(asctime)s %(message)s',
level=level, datefmt='%Y-%m-%d %H:%M:%S %Z')
if len(sys.argv) > 1:
backgrounds_dir = sys.argv[1]
else:
backgrounds_dir = DEFAULT_IMAGE_DIR
# infinite loop: Press Ctrl+C to interrupt it
#NOTE: here's some arbitrary logic: modify for you needs e.g., break
# after the first image found
timeout = TIMEOUT_MIN # seconds
for i in itertools.cycle(xrange(timeout, DAY_IN_SECONDS)):
found = False
try:
for url, filename in WallbaseImages(
categories=[CATEGORY_WG, CATEGORY_HR, CATEGORY_W],
purity=PURITY_SFW,
thumbs_per_page=60):
res = download(url, backgrounds_dir, extensions=('.jpg',),
filename=filename)
if res and res.path:
found = True
set_background(res.path)
# don't hammer the site
timeout = max(TIMEOUT_MIN, i % DAY_IN_SECONDS)
_sleep(random.randint(timeout, timeout + TIMEOUT_DELTA))
except Exception: # pylint: disable=W0703
logging.exception('unexpected error')
_sleep(timeout)
else:
if not found:
logging.error('failed to retrieve any images')
_sleep(timeout)
timeout = (timeout * 2) % DAY_IN_SECONDS
def _sleep(timeout):
"""Add logging to time.sleep() call."""
logging.debug('sleep for %s seconds', timeout)
time.sleep(timeout)
main()
答案 2 :(得分：-1)
试图实现一个使用PIL库在图像上写文本的python脚本，然后使用Gio类更新Gnome背景“picture-uri”以指向该图像。 python脚本会在两个图像之间打乒乓，以便始终修改未使用的图像，然后尝试通过更新“设置”来“切换”。这是为了避免任何闪烁，因为修改当前背景会直接将其丢弃。虽然在shell中直接调用脚本但我很少看到任何问题，但在cronjob中它根本不会更新pong。我使用了同步和应用，并在尝试切换图像之前等待几分钟。没工作。尝试将cron作为用户（su -c“cmd”用户）并且也无效。
当我注意到Gnome将检测到后台文件中的任何更改并进行更新时，最后放弃了ping pong方法。所以放弃了ping pong方法并转到临时文件，我只是使用shutil库复制当前背景。奇迹般有效。