1 """
2 The live module provides a mechanism of periodically checking which games are
3 being actively played.
4
5 It requires the third party library pytz to be
6 installed, which makes sure game times are compared properly with respect
7 to time zones. pytz can be downloaded from PyPI:
8 http://pypi.python.org/pypi/pytz/
9
10 It works by periodically downloading data from NFL.com for games that started
11 before the current time. Once a game completes, the live module stops asking
12 NFL.com for data for that game.
13
14 If there are no games being actively played (i.e., it's been more than N hours
15 since the last game started), then the live module sleeps for longer periods
16 of time.
17
18 Thus, the live module can switch between two different modes: active and
19 inactive.
20
21 In the active mode, the live module downloads data from NFL.com in
22 short intervals. A transition to an inactive mode occurs when no more games
23 are being played.
24
25 In the inactive mode, the live module only checks if a game is playing (or
26 about to play) every 15 minutes. If a game is playing or about to play, the
27 live module switches to the active mode. Otherwise, it stays in the inactive
28 mode.
29
30 With this strategy, if the live module is working properly, you could
31 theoretically keep it running for the entire season.
32
33 (N.B. Half-time is ignored. Games are either being actively played or not.)
34
35 Alpha status
36 ============
37 This module is emphatically in alpha status. I believe things will work OK for
38 the regular season, but the postseason brings new challenges. Moreover, it
39 will probably affect the API at least a little bit.
40 """
41 import datetime
42 import time
43 import urllib2
44 import xml.dom.minidom as xml
45
46 try:
47 import pytz
48 except ImportError:
49 pass
50
51 import nflgame
52 import nflgame.game
53 import nflgame.schedule
54
55
56
57
58 _MAX_GAME_TIME = 60 * 60 * 6
59 """
60 The assumed maximum time allowed for a game to complete. This is used to
61 determine whether a particular game that isn't over is currently active.
62 """
63
64 _WEEK_INTERVAL = 60 * 60 * 12
65 """
66 How often to check what the current week is. By default, it is twice a day.
67 """
68
69 _CUR_SCHEDULE_URL = "http://www.nfl.com/liveupdate/scorestrip/ss.xml"
70 """
71 Pinged infrequently to discover the current week number, year and week type.
72 The actual schedule of games is taken from the schedule module.
73 """
74
75
76 _POST_URL = "http://static.nfl.com/liveupdate/scorestrip/postseason/ss.xml"
77 """
78 The URL for the XML schedule of the post season. This is only used
79 during the post season.
80
81 TODO: How do we know if it's the post season?
82 """
83
84 _EASTERN_TZ = pytz.timezone('US/Eastern')
85 """Used to convert game times in EST to UTC."""
86
87 _cur_week = None
88 """The current week. It is updated infrequently automatically."""
89
90 _cur_year = None
91 """The current year. It is updated infrequently automatically."""
92
93 _preseason = False
94 """True when it's the preseason."""
95
96 _regular = False
97 """True when it's the regular season."""
98
99 _completed = []
100 """
101 A list of game eids that have been completed since the live module started
102 checking for updated game stats.
103 """
104
105
107 """
108 Returns a tuple (year, week) where year is the current year of the season
109 and week is the current week number of games being played.
110 i.e., (2012, 3).
111
112 N.B. This always downloads the schedule XML data.
113 """
114 dom = xml.parse(urllib2.urlopen(_CUR_SCHEDULE_URL))
115 gms = dom.getElementsByTagName('gms')[0]
116 year = int(gms.getAttribute('y'))
117 week = int(gms.getAttribute('w'))
118 return (year, week)
119
120
122 """
123 Returns a list of game.Games of games that are currently playing.
124 This fetches all current information from NFL.com.
125
126 If either year or week is none, then the current year and week are
127 fetched from the schedule on NFL.com. If they are *both* provided, then
128 the schedule from NFL.com won't need to be downloaded, and thus saving
129 time.
130
131 So for example::
132
133 year, week = nflgame.live.current_year_and_week()
134 while True:
135 games = nflgame.live.current_games(year, week)
136 # Do something with games
137 time.sleep(60)
138
139 The kind parameter specifies whether to fetch preseason, regular season
140 or postseason games. Valid values are PRE, REG and POST.
141 """
142 if year is None or week is None:
143 year, week = current_year_and_week()
144
145 guesses = []
146 now = _now()
147 games = _games_in_week(year, week, kind='REG')
148 for info in games:
149 gametime = _game_datetime(info)
150 if gametime >= now:
151 if (gametime - now).total_seconds() <= 60 * 15:
152 guesses.append(info['eid'])
153 elif (now - gametime).total_seconds() <= _MAX_GAME_TIME:
154 guesses.append(info['eid'])
155
156
157
158
159
160 current = []
161 for guess in guesses:
162 game = nflgame.game.Game(guess['eid'])
163 if game.playing():
164 current.append(game)
165 return current
166
167
168 -def run(callback, active_interval=15, inactive_interval=900, stop=None):
169 """
170 Starts checking for games that are currently playing.
171
172 Every time there is an update, callback will be called with two lists:
173 active and completed. The active list is a list of game.Game that are
174 currently being played. The completed list is a list of game.Game that
175 have just finished. A game will appear in the completed list only once,
176 after which that game will not be in either the active or completed lists.
177 No game can ever be in both lists at the same time.
178
179 It is possible that a game in the active list is not yet playing because
180 it hasn't started yet. It ends up in the active list because the "pregame"
181 has started on NFL.com's GameCenter web site, and sometimes game data is
182 partially filled. When this is the case, the 'playing' method on
183 a nflgame.game.Game will return False.
184
185 When in the active mode (see live module description), active_interval
186 specifies the number of seconds to wait between checking for updated game
187 data. Please do not make this number too low to avoid angering NFL.com.
188 If you anger them too much, it is possible that they could ban your IP
189 address.
190
191 Note that NFL.com's GameCenter page is updated every 15 seconds, so
192 setting the active_interval much smaller than that is wasteful.
193
194 When in the inactive mode (see live module description), inactive_interval
195 specifies the number of seconds to wait between checking whether any games
196 have started or are about to start.
197
198 With the default parameters, run will never stop. However, you may set
199 stop to a Python datetime.datetime value. After time passes the stopping
200 point, run will quit. (Technically, it's possible that it won't quit until
201 at most inactive_interval seconds after the stopping point is reached.)
202 The stop value is compared against datetime.datetime.now().
203 """
204 active = False
205 last_week_check = _update_week_number()
206
207
208
209
210 for info in _active_games(inactive_interval):
211 game = nflgame.game.Game(info['eid'])
212
213
214
215 if game is None:
216 continue
217
218
219
220 if game.game_over():
221 _completed.append(info['eid'])
222
223 while True:
224 if stop is not None and datetime.datetime.now() > stop:
225 return
226
227 if time.time() - last_week_check > _WEEK_INTERVAL:
228 last_week_check = _update_week_number()
229
230 games = _active_games(inactive_interval)
231 if active:
232 active = _run_active(callback, games)
233 if not active:
234 continue
235 time.sleep(active_interval)
236 else:
237 active = not _run_inactive(games)
238 if active:
239 continue
240 time.sleep(inactive_interval)
241
242
244 """
245 The active mode traverses each of the active games and fetches info for
246 each from NFL.com.
247
248 Then each game (that has info available on NFL.com---that is, the game
249 has started) is added to one of two lists: active and completed, which
250 are passed as the first and second parameters to callback. A game is
251 put in the active list if it's still being played, and into the completed
252 list if it has finished. In the latter case, it is added to a global store
253 of completed games and will never be passed to callback again.
254 """
255
256
257 if len(games) == 0:
258 return False
259
260 active, completed = [], []
261 for info in games:
262 game = nflgame.game.Game(info['eid'])
263
264
265
266 if game is None:
267 continue
268
269
270 if game.game_over():
271 completed.append(game)
272 _completed.append(info['eid'])
273 else:
274 active.append(game)
275
276 callback(active, completed)
277 return True
278
279
281 """
282 The inactive mode simply checks if there are any active games. If there
283 are, inactive mode needs to stop and transition to active mode---thus
284 we return False. If there aren't any active games, then the inactive
285 mode should continue, where we return True.
286
287 That is, so long as there are no active games, we go back to sleep.
288 """
289 return len(games) == 0
290
291
293 """
294 Returns a list of all active games. In this case, an active game is a game
295 that will start within inactive_interval seconds, or has started within
296 _MAX_GAME_TIME seconds in the past.
297 """
298 games = _games_in_week(_cur_year, _cur_week, kind='REG')
299 active = []
300 for info in games:
301 if not _game_is_active(info, inactive_interval):
302 continue
303 active.append(info)
304 return active
305
306
308 """
309 A list for the games matching the year/week/kind parameters.
310
311 The kind parameter specifies whether to fetch preseason, regular season
312 or postseason games. Valid values are PRE, REG and POST.
313 """
314 return nflgame._search_schedule(year, week, kind=kind)
315
316
318 """
319 Returns true if the game is active. A game is considered active if the
320 game start time is in the past and not in the completed list (which is
321 a private module level variable that is populated automatically) or if the
322 game start time is within inactive_interval seconds from starting.
323 """
324 gametime = _game_datetime(gameinfo)
325 now = _now()
326 if gametime >= now:
327 return (gametime - now).total_seconds() <= inactive_interval
328 return gameinfo['eid'] not in _completed
329
330
332 hour, minute = gameinfo['time'].strip().split(':')
333 d = datetime.datetime(gameinfo['year'], gameinfo['month'], gameinfo['day'],
334 (int(hour) + 12) % 24, int(minute))
335 return _EASTERN_TZ.localize(d).astimezone(pytz.utc)
336
337
339 return datetime.datetime.now(pytz.utc)
340
341
352