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 _cur_week = None
85 """The current week. It is updated infrequently automatically."""
86
87 _cur_year = None
88 """The current year. It is updated infrequently automatically."""
89
90 _preseason = False
91 """True when it's the preseason."""
92
93 _regular = False
94 """True when it's the regular season."""
95
96 _completed = []
97 """
98 A list of game eids that have been completed since the live module started
99 checking for updated game stats.
100 """
101
102
104 """
105 Returns a tuple (year, week) where year is the current year of the season
106 and week is the current week number of games being played.
107 i.e., (2012, 3).
108
109 N.B. This always downloads the schedule XML data.
110 """
111 dom = xml.parse(urllib2.urlopen(_CUR_SCHEDULE_URL))
112 gms = dom.getElementsByTagName('gms')[0]
113 year = int(gms.getAttribute('y'))
114 week = int(gms.getAttribute('w'))
115 return (year, week)
116
117
119 """
120 Returns a list of game.Games of games that are currently playing.
121 This fetches all current information from NFL.com.
122
123 If either year or week is none, then the current year and week are
124 fetched from the schedule on NFL.com. If they are *both* provided, then
125 the schedule from NFL.com won't need to be downloaded, and thus saving
126 time.
127
128 So for example::
129
130 year, week = nflgame.live.current_year_and_week()
131 while True:
132 games = nflgame.live.current_games(year, week)
133 # Do something with games
134 time.sleep(60)
135
136 The kind parameter specifies whether to fetch preseason, regular season
137 or postseason games. Valid values are PRE, REG and POST.
138 """
139 if year is None or week is None:
140 year, week = current_year_and_week()
141
142 guesses = []
143 now = _now()
144 games = _games_in_week(year, week, kind='REG')
145 for info in games:
146 gametime = _game_datetime(info)
147 if gametime >= now:
148 if (gametime - now).total_seconds() <= 60 * 15:
149 guesses.append(info['eid'])
150 elif (now - gametime).total_seconds() <= _MAX_GAME_TIME:
151 guesses.append(info['eid'])
152
153
154
155
156
157 current = []
158 for guess in guesses:
159 game = nflgame.game.Game(guess['eid'])
160 if game.playing():
161 current.append(game)
162 return current
163
164
165 -def run(callback, active_interval=15, inactive_interval=900, stop=None):
166 """
167 Starts checking for games that are currently playing.
168
169 Every time there is an update, callback will be called with two lists:
170 active and completed. The active list is a list of game.Game that are
171 currently being played. The completed list is a list of game.Game that
172 have just finished. A game will appear in the completed list only once,
173 after which that game will not be in either the active or completed lists.
174 No game can ever be in both lists at the same time.
175
176 It is possible that a game in the active list is not yet playing because
177 it hasn't started yet. It ends up in the active list because the "pregame"
178 has started on NFL.com's GameCenter web site, and sometimes game data is
179 partially filled. When this is the case, the 'playing' method on
180 a nflgame.game.Game will return False.
181
182 When in the active mode (see live module description), active_interval
183 specifies the number of seconds to wait between checking for updated game
184 data. Please do not make this number too low to avoid angering NFL.com.
185 If you anger them too much, it is possible that they could ban your IP
186 address.
187
188 Note that NFL.com's GameCenter page is updated every 15 seconds, so
189 setting the active_interval much smaller than that is wasteful.
190
191 When in the inactive mode (see live module description), inactive_interval
192 specifies the number of seconds to wait between checking whether any games
193 have started or are about to start.
194
195 With the default parameters, run will never stop. However, you may set
196 stop to a Python datetime.datetime value. After time passes the stopping
197 point, run will quit. (Technically, it's possible that it won't quit until
198 at most inactive_interval seconds after the stopping point is reached.)
199 The stop value is compared against datetime.datetime.now().
200 """
201 active = False
202 last_week_check = _update_week_number()
203
204
205
206
207 for info in _active_games(inactive_interval):
208 game = nflgame.game.Game(info['eid'])
209
210
211
212 if game is None:
213 continue
214
215
216
217 if game.game_over():
218 _completed.append(info['eid'])
219
220 while True:
221 if stop is not None and datetime.datetime.now() > stop:
222 return
223
224 if time.time() - last_week_check > _WEEK_INTERVAL:
225 last_week_check = _update_week_number()
226
227 games = _active_games(inactive_interval)
228 if active:
229 active = _run_active(callback, games)
230 if not active:
231 continue
232 time.sleep(active_interval)
233 else:
234 active = not _run_inactive(games)
235 if active:
236 continue
237 time.sleep(inactive_interval)
238
239
241 """
242 The active mode traverses each of the active games and fetches info for
243 each from NFL.com.
244
245 Then each game (that has info available on NFL.com---that is, the game
246 has started) is added to one of two lists: active and completed, which
247 are passed as the first and second parameters to callback. A game is
248 put in the active list if it's still being played, and into the completed
249 list if it has finished. In the latter case, it is added to a global store
250 of completed games and will never be passed to callback again.
251 """
252
253
254 if len(games) == 0:
255 return False
256
257 active, completed = [], []
258 for info in games:
259 game = nflgame.game.Game(info['eid'])
260
261
262
263 if game is None:
264 continue
265
266
267 if game.game_over():
268 completed.append(game)
269 _completed.append(info['eid'])
270 else:
271 active.append(game)
272
273 callback(active, completed)
274 return True
275
276
278 """
279 The inactive mode simply checks if there are any active games. If there
280 are, inactive mode needs to stop and transition to active mode---thus
281 we return False. If there aren't any active games, then the inactive
282 mode should continue, where we return True.
283
284 That is, so long as there are no active games, we go back to sleep.
285 """
286 return len(games) == 0
287
288
290 """
291 Returns a list of all active games. In this case, an active game is a game
292 that will start within inactive_interval seconds, or has started within
293 _MAX_GAME_TIME seconds in the past.
294 """
295 games = _games_in_week(_cur_year, _cur_week, kind='REG')
296 active = []
297 for info in games:
298 if not _game_is_active(info, inactive_interval):
299 continue
300 active.append(info)
301 return active
302
303
305 """
306 A list for the games matching the year/week/kind parameters.
307
308 The kind parameter specifies whether to fetch preseason, regular season
309 or postseason games. Valid values are PRE, REG and POST.
310 """
311 return nflgame._search_schedule(year, week, kind=kind)
312
313
315 """
316 Returns true if the game is active. A game is considered active if the
317 game start time is in the past and not in the completed list (which is
318 a private module level variable that is populated automatically) or if the
319 game start time is within inactive_interval seconds from starting.
320 """
321 gametime = _game_datetime(gameinfo)
322 now = _now()
323 if gametime >= now:
324 return (gametime - now).total_seconds() <= inactive_interval
325 return gameinfo['eid'] not in _completed
326
327
329 hour, minute = gameinfo['time'].strip().split(':')
330 d = datetime.datetime(gameinfo['year'], gameinfo['month'], gameinfo['day'],
331 (int(hour) + 12) % 24, int(minute))
332 return pytz.timezone('US/Eastern').localize(d).astimezone(pytz.utc)
333
334
336 return datetime.datetime.now(pytz.utc)
337
338
349