我决定对天气托盘小程序 found here 进行一些修改。
经过多次测试，我发现 update_tray（）在我的计算机花费一些时间休眠后停止更新。只手动更新它。
在检查代码后，我发现负责更新的行是：
gobject.timeout_add_seconds(self.args.delta * 60, self.update_tray)
的 gobject documentation 说这个函数被反复调用，直到它返回FALSE，点，超时被自动销毁和功能将不会被再次调用处。但似乎计数器被破坏了，因为系统时钟突然变化了。
我想知道如何在发生此问题时重新启动计时器。这是完整的代码：
#!/usr/bin/env python2
# -*- coding: utf-8 -*-
#
# Released under the terms of the GNU GPLv2.
#
import gtk
import gobject
import time
import webbrowser
from urllib2 import urlopen, URLError
from argparse import ArgumentParser
from xml.dom import minidom
parser = ArgumentParser(description='Simple weather applet', epilog='Written by Roman Komkov and updated at 06.06.2012.\nPlease, report bugs to <r.komkov@gmail.com>')
parser.add_argument('-l', '--location', required=True, metavar='WOEID', help='location WOEID (more on http://developer.yahoo.com/weather/)')
parser.add_argument('-u', '--units', choices=['c','f'], default='c', metavar='c|f', help='units to display')
parser.add_argument('-d', '--delta', default='10', type=int, metavar='N', help='timeout in minutes between next weather data query')
parser.add_argument('-a', '--advanced', action = 'store_true', default=False, help='Advanced tooltip')
class Api:
def __init__(self, location, units):
self.params = (location,units)
self.url = 'http://xml.weather.yahoo.com/forecastrss?w=%s&u=%s'
self.namespace = 'http://xml.weather.yahoo.com/ns/rss/1.0'
self.website = 'http://weather.yahoo.com/'
self.codes = { #code:icon name
'0':'weather-severe-alert',
'1':'weather-severe-alert',
'2':'weather-severe-alert',
'3':'weather-severe-alert',
'4':'weather-storm',
'5':'weather-snow-rain',
'6':'weather-snow-rain',
'7':'weather-snow',
'8':'weather-freezing-rain',
'9':'weather-fog',
'10':'weather-freezing-rain',
'11':'weather-showers',
'12':'weather-showers',
'13':'weather-snow',
'14':'weather-snow',
'15':'weather-snow',
'16':'weather-snow',
'17':'weather-snow',
'18':'weather-snow',
'19':'weather-fog',
'20':'weather-fog',
'21':'weather-fog',
'22':'weather-fog',
'23':'weather-few-clouds',
'24':'weather-few-clouds',
'25':'weather-few-clouds',
'26':'weather-overcast',
'27':'weather-clouds-night',
'28':'weather-clouds',
'29':'weather-few-clouds-night',
'30':'weather-few-clouds',
'31':'weather-clear-night',
'32':'weather-clear',
'33':'weather-clear-night',
'34':'weather-clear',
'35':'weather-snow-rain',
'36':'weather-clear',
'37':'weather-storm',
'38':'weather-storm',
'39':'weather-storm',
'40':'weather-showers-scattered',
'41':'weather-snow',
'42':'weather-snow',
'43':'weather-snow',
'44':'weather-few-clouds',
'45':'weather-storm',
'46':'weather-snow',
'47':'weather-storm',
'3200':'stock-unknown'
}
def conv_direction(self, value):
value = int(value)
if value >= 0 and value < 45:
return u'\u2191 (N)'
elif value >= 45 and value < 90:
return u'\u2197 (NE)'
elif value >= 90 and value < 135:
return u'\u2192 (E)'
elif value >= 135 and value < 180:
return u'\u2198 (SE)'
elif value >= 180 and value < 225:
return u'\u2193 (S)'
elif value >= 225 and value < 270:
return u'\u2199 (SW)'
elif value >= 270 and value < 315:
return u'\u2190 (W)'
elif value >= 315 and value < 360:
return u'\u2196 (NW)'
else:
return u'\u2191 (N)'
def get_data(self):
try:
url = self.url % self.params
dom = minidom.parse(urlopen(url))
units_node = dom.getElementsByTagNameNS(self.namespace, 'units')[0]
units = {'temperature': units_node.getAttribute('temperature'),
'distance': units_node.getAttribute('distance'),
'pressure': units_node.getAttribute('pressure'),
'speed': units_node.getAttribute('speed')}
forecasts = []
for node in dom.getElementsByTagNameNS(self.namespace, 'forecast'):
forecasts.append({
'date': node.getAttribute('date'),
'low': node.getAttribute('low')+u'\u00B0 '+units['temperature'],
'high': node.getAttribute('high')+u'\u00B0 '+units['temperature'],
'condition': node.getAttribute('text'),
'icon': self.codes.get(node.getAttribute('code'))
})
condition = dom.getElementsByTagNameNS(self.namespace, 'condition')[0]
location = dom.getElementsByTagNameNS(self.namespace, 'location')[0]
wind = dom.getElementsByTagNameNS(self.namespace, 'wind')[0]
atmosphere = dom.getElementsByTagNameNS(self.namespace, 'atmosphere')[0]
return {
'current_condition': condition.getAttribute('text'),
'current_icon': self.codes.get(condition.getAttribute('code')),
'current_temp': condition.getAttribute('temp')+u'\u00B0 '+units['temperature'],
'extra':{
'wind': {'direction':self.conv_direction(wind.getAttribute('direction')),
'speed':wind.getAttribute('speed')+' '+units['speed']},
'atmosphere': {'humidity':atmosphere.getAttribute('humidity')+'%',
'visibility':atmosphere.getAttribute('visibility')+' '+units['distance'],
'pressure':atmosphere.getAttribute('pressure')+' '+units['pressure']}},
'forecasts': forecasts,
'location' : {'city' : location.getAttribute('city'),'country' : location.getAttribute('country')}
}
except URLError, ex:
return None
class MainApp:
def __init__(self,args):
self.args = args
self.weather = None
self.tooltip = None
self.tray = gtk.StatusIcon()
self.tray.connect('popup-menu', self.on_right_click)
self.tray.connect('activate', self.on_left_click)
self.tray.set_has_tooltip(True)
if self.args.advanced:
self.tray.connect('query-tooltip', self.on_tooltip_advanced)
self.api = Api(self.args.location, self.args.units)
self.update_tray()
gobject.timeout_add_seconds(self.args.delta * 60, self.update_tray)
def on_tooltip_advanced(self, widget, x, y, keyboard_mode, tooltip):
#if self.tooltip:
#tooltip.set_text(self.tooltip)
if self.weather:
weather = self.weather
tooltip_text = '%s\n%s' % (self.weather['current_temp'],self.weather['current_condition'])
vbox = gtk.VBox()
header = gtk.Label()
header.set_markup('<u><b>'+self.weather['location']['city']+', '+self.weather['location']['country']+'</b></u>')
header.set_alignment(1.0, 0.5)
separator_h = gtk.HSeparator()
hbox = gtk.HBox()
now_image = gtk.Image()
now_image.set_padding(0,5)
now_image.set_pixel_size(48)
now_image.set_from_icon_name(weather['current_icon'],48)
now_label = gtk.Label()
now_label.set_markup('<b>'+tooltip_text+'</b>')
now_label.set_padding(5,5)
table = gtk.Table(columns=2, homogeneous=False)
u = 0
l = 1
for k,v in self.weather['extra'].iteritems():
h_label = gtk.Label()
h_label.set_markup('<b>'+k+'</b>')
h_label.set_alignment(0.0, 0.5)
h_label.set_padding(5,0)
table.attach(h_label,0,1,u,l)
for i,j in v.iteritems():
u +=1
l +=1
k_label = gtk.Label(i)
k_label.set_alignment(0.0, 0.5)
v_label = gtk.Label(j)
v_label.set_alignment(0.0, 0.5)
table.attach(k_label,0,1,u,l)
table.attach(v_label,1,2,u,l)
u +=1
l +=1
hbox.pack_start(now_image, False, False, 0)
hbox.pack_start(now_label, False, False, 0)
vbox.pack_start(header, True, False, 0)
vbox.pack_start(separator_h, False, False, 0)
vbox.pack_start(hbox, False, False, 0)
vbox.pack_start(table, False, False, 0)
vbox.show_all()
tooltip.set_custom(vbox)
else:
tooltip.set_text('Connection error!')
return True
def on_refresh(self,widget):
self.update_tray()
def on_right_click(self, icon, event_button, event_time):
menu = gtk.Menu()
refresh = gtk.MenuItem('Refresh')
refresh.show()
refresh.connect('activate', self.on_refresh)
quit = gtk.MenuItem('Quit')
quit.show()
quit.connect('activate', gtk.main_quit)
menu.append(refresh)
menu.append(quit)
menu.popup(None, None, gtk.status_icon_position_menu,
event_button, event_time, self.tray)
def on_left_click(self, widget):
webbrowser.open(self.api.website)
def update_tray(self):
self.weather = self.api.get_data()
if self.weather != None:
self.tray.set_from_icon_name(self.weather['current_icon'])
if not self.args.advanced:
tooltip_text = '%s / %s' % (self.weather['current_temp'],self.weather['current_condition'])
self.tray.set_tooltip_markup(tooltip_text)
else:
if not self.args.advanced:
self.tray.set_tooltip_text('Connection error!')
self.tray.set_from_stock('gtk-dialog-error')
return True
if __name__ == "__main__":
try:
args = parser.parse_args()
MainApp(args)
gtk.main()
except KeyboardInterrupt:
pass
根据@ J.F.Sebastian的要求，这是一个较小的代码示例：
#!/usr/bin/env python2
# -*- coding: utf-8 -*-
import gtk, gobject, time
from datetime import datetime
class MainApp:
def __init__(self):
self.update_tray()
gobject.timeout_add_seconds(15 * 60, self.update_tray)
def update_tray(self):
print time.strftime('%c')
return True
if __name__ == "__main__":
try:
MainApp()
gtk.main()
except KeyboardInterrupt:
pass
更新：我将其设置为每分钟更新，休眠，并在返回时，脚本继续工作。 10分钟后我得到了一个 socket.error ，它就不再更新了。我认为问题不在于互联网连接，因为我无法通过拔掉电缆来重现它。现在，我的问题是：如何在发现此错误时重新启动计数器，或者避免此错误，因为 get_data已经有try:语句？
Traceback (most recent call last):
File "weatherboy", line 333, in update_tray
self.weather = self.api.get_data()
File "weatherboy", line 145, in get_data
dom = minidom.parse(urlopen(url))
File "/usr/lib/python2.7/urllib2.py", line 127, in urlopen
return _opener.open(url, data, timeout)
File "/usr/lib/python2.7/urllib2.py", line 401, in open
response = self._open(req, data)
File "/usr/lib/python2.7/urllib2.py", line 419, in _open
'_open', req)
File "/usr/lib/python2.7/urllib2.py", line 379, in _call_chain
result = func(*args)
File "/usr/lib/python2.7/urllib2.py", line 1211, in http_open
return self.do_open(httplib.HTTPConnection, req)
File "/usr/lib/python2.7/urllib2.py", line 1184, in do_open
r = h.getresponse(buffering=True)
File "/usr/lib/python2.7/httplib.py", line 1034, in getresponse
response.begin()
File "/usr/lib/python2.7/httplib.py", line 407, in begin
version, status, reason = self._read_status()
File "/usr/lib/python2.7/httplib.py", line 365, in _read_status
line = self.fp.readline()
File "/usr/lib/python2.7/socket.py", line 447, in readline
data = self._sock.recv(self._rbufsize)
socket.error: [Errno 104] Connection reset by peer
答案 0 :(得分：2)
update_tray()应该返回True。未处理的socket.error可以防止这种情况发生。您可以使用except EnvironmentError代替except URLError来捕获get_data()中更广泛的错误。
要忽略其他类型的错误，您可以将try: ... except Exception: log_it()添加到update_tray()。