class RouteInfoSearcher(object):
def __init__(self, api_key, size_matrix=10, time_delay=5):
self.client = googlemaps.Client(api_key)
self.db = DBManager(path='./spots_tools.db')
self.size_matrix = size_matrix
self.time_delay = time_delay
# extract id & location from SpotInfo DB
print('Extracting spots\' info from SpotInfo DB...', end=' ')
self.db.run_query('SELECT id, latitude, longitude FROM SpotInfo')
list_rows = self.db.fetch_all()
print('Success!')
# build the objects used for searching
self.num_spots = len(list_rows)
self.list_ids = [row['id'] for row in list_rows]
self.list_lats = [row['latitude'] for row in list_rows]
self.list_lngs = [row['longitude'] for row in list_rows]
# list of (index_min, index_max + 1) for each submatrix
self.list_ranges = [
(i, min(i + self.size_matrix, self.num_spots))
for i in xrange(0, self.num_spots, self.size_matrix)
]
def try_transit(self, info_routes, range_start, range_end):
print('- Trying the transit mode...', end=' ')
input_start = [
'place_id:%s' % self.list_ids[i] for i in xrange(*range_start)
]
input_end = [
'place_id:%s' % self.list_ids[i] for i in xrange(*range_end)
]
response = getattr(self.client, 'distance_matrix')(
origins=input_start,
destinations=input_end,
units='metric',
mode='transit',
transit_routing_preference='less_walking')
num_tries, num_fails = 0, 0
if response['status'] == 'OK':
for i in xrange(*range_start):
row = response['rows'][i - range_start[0]]['elements']
for j in xrange(*range_end):
item = row[j - range_end[0]]
num_tries += 1
if item['status'] == 'OK':
info_routes[i][j] = {
'time': item['duration']['value'],
'distance': item['distance']['value']
}
else:
num_fails += 1
print('%d / %d failed!' % (num_fails, num_tries))
return num_fails == 0
def try_walking(self, info_routes, range_start, range_end):
print('- Trying the walking mode...', end=' ')
num_tries, num_fails = 0, 0
for i in xrange(*range_start):
for j in xrange(*range_end):
if info_routes[i][j] is None:
response = getattr(self.client, 'directions')(
origin='place_id:%s' % self.list_ids[i],
destination='place_id:%s' % self.list_ids[j],
units='metric',
mode='walking')
num_tries += 1
if response and response[0]['legs']:
item = response[0]['legs'][0]
info_routes[i][j] = {
'time': item['duration']['value'],
'distance': item['distance']['value']
}
else:
num_fails += 1
print('%d / %d failed!' % (num_fails, num_tries))
return num_fails == 0
def try_guessing(self, info_routes, range_start, range_end):
print('- Trying to guess using the haversine formula...', end=' ')
num_tries = 0
for i in xrange(*range_start):
for j in xrange(*range_end):
if info_routes[i][j] is None:
distance = calc_distance(self.list_lats[i],
self.list_lngs[i],
self.list_lats[j],
self.list_lngs[j])
num_tries += 1
info_routes[i][j] = {
'time': distance / 1.23, # walking speed: 1.23m/s,
'distance': distance
}
print('Success! (%d)' % num_tries)
def search(self):
info_routes = [[None] * self.num_spots for _ in xrange(self.num_spots)]
try:
for range_start in self.list_ranges:
for range_end in self.list_ranges:
print('Searching (%d ~ %d) X (%d ~ %d):' %
(range_start[0], range_start[1] - 1, range_end[0],
range_end[1] - 1))
# try the transit mode (i.e public transportations)
if self.try_transit(info_routes, range_start, range_end):
continue
# try the walking mode
if self.try_walking(info_routes, range_start, range_end):
continue
# try to guess using the haversine formula
self.try_guessing(info_routes, range_start, range_end)
print('Delaying: %d seconds...' % self.time_delay, end=' ')
time.sleep(self.time_delay)
print('Success!')
except googlemaps.exceptions.Timeout:
print('\nTimeout! We\'ll just guess the remaining routes.')
range_whole = (0, self.num_spots)
self.try_guessing(info_routes, range_whole, range_whole)
# insert the result into RouteInfo DB
print('Inserting the result into RouteInfo DB:')
for i in xrange(self.num_spots):
for j in xrange(self.num_spots):
print('- Route %d -> %d...' % (i, j), end=' ')
self.db.run_query(
'INSERT OR REPLACE INTO RouteInfo ('
' startId, endId, time, distance'
') VALUES (?, ?, ?, ?)', self.list_ids[i],
self.list_ids[j], info_routes[i][j]['time'],
info_routes[i][j]['distance'])
print('Success!')
