def get_avg(exchanges):
"""Calculate average last value from the specified exchanges
Args:
exchanges (LIST): Exchanges' names
Returns:
FLOAT: Average value
"""
values = []
for exchange in active_exchanges():
exchange_lower = exchange.name.lower().replace(' ', '_')
if exchange_lower in exchanges:
res = get_alternate_value(exchange, position='previous')
if res:
last, buy, trend = res
values.append(last)
avg = reduce(lambda x, y: x + y, values) / len(values)
return avg
def get_exchanges_info():
"""Generate response used by the exchanges API
Returns:
DICT: Exchanges info and last value
"""
now = datetime.now()
res = {
'_timestamp': now.strftime('%a %b %d %Y, %H:%M:%S'),
}
for exchange in active_exchanges():
if exchange.key_buy:
previous = last = buy = trend = None
# Get the last/buy values and trend computed by the get_values task
previous = get_alternate_value(exchange, position='previous')
if previous:
last, buy, trend = previous
# Get the last value history from the last 10 days
query = Graph.query.filter_by(
exchange_id=exchange.id).order_by(
Graph.date.desc()).limit(10).all()
history = []
for assoc in query:
history.append(assoc.last)
key = exchange.name.lower().replace(' ', '_')
res[key] = {
'currency': exchange.currency_to.name,
'buy': buy,
'sell': last,
'history': history[::-1],
'trend': trend or None,
}
return res
def get_values():
"""
Manager command to get last values from all active exchanges
"""
for exchange in active_exchanges():
ticker = exchange.url + exchange.api
subject = '[ERROR] %s exchange' % exchange.name
error_msg = "Exchange: %s\nTicker: %s\nException: " % (exchange.name,
ticker)
try:
previous_last = last = buy = trend = None
last = exchange.get_value(exchange.key_last)
if exchange.key_buy:
buy = exchange.get_value(exchange.key_buy)
# Close session opened after the execution of get_value method
db.session.close()
# Also get previous to calculate trend
res = get_alternate_value(exchange, position='previous')
if res:
previous_last, previous_buy, trend = res
if previous_last and last:
if previous_last < last:
trend = 'up'
elif previous_last > last:
trend = 'down'
else:
trend = 'equal'
assoc = Association(
exchange_id=exchange.id,
last=last,
buy=buy,
trend=trend or None,
date=date.today(),
time=datetime.now().time()
)
if assoc.last:
print '%s: %s %s %s' % (exchange.name,
assoc.last,
exchange.currency_to.name,
trend or '')
db.session.add(assoc)
else:
raise Exception
except Exception as err:
if not err.message:
err.message = 'Connection Error. Ticker API is down.'
print subject + ': ' + str(err.message)
if app.config.get('ENABLE_MAIL_NOTIFICATIONS', False):
send_async_email(subject, error_msg + str(err.message))
finally:
db.session.commit()
db.session.close()
def get_graphs():
"""
Store graph data in database to be used later by the graphs API
"""
# List of exchanges to store values for a candlesticks graph
candlesticks_exchanges = ['Bitstamp']
for exchange in active_exchanges():
ticker = exchange.url + exchange.api
subject = '[ERROR] %s exchange (GRAPH)' % exchange.name
error_msg = "Exchange: %s\nTicker: %s\nException: " % (exchange.name,
ticker)
try:
last = opn = high = low = close = volume = None
last = exchange.get_value(exchange.key_last)
# Close session opened after the execution of get_value method
db.session.close()
if exchange.name in candlesticks_exchanges:
# Get the open value (the first value of the day)
opn, buy, trend = get_alternate_value(exchange,
position='first')
# Get ticker to obtain additional values to show in graph
response = get_ticker_response(exchange)
if opn and response:
# Serialize ticker response
json = loads(response.content)
close = json['last'] or None,
high = json['high'] or None,
low = json['low'] or None,
volume = float(json['volume']) or None,
except ConnectionError:
if not last:
previous = get_alternate_value(exchange, position='previous')
if previous:
last = previous[0]
excep = 'Error connecting with API. Using previous value.'
if app.config.get('ENABLE_MAIL_NOTIFICATIONS', False):
send_async_email(subject, error_msg + excep)
else:
excep = 'Error connecting with API. No previous value get.'
if app.config.get('ENABLE_MAIL_NOTIFICATIONS', False):
send_async_email(subject, error_msg + excep)
print subject + ': ' + excep
except Exception as err:
print subject + ': ' + str(err.message)
if app.config.get('ENABLE_MAIL_NOTIFICATIONS', False):
send_async_email(subject, error_msg + str(err.message))
finally:
try:
# Write obtained values to database
graph = Graph(
exchange_id=exchange.id,
last=last,
opn=opn,
close=close,
high=high,
low=low,
volume=volume,
date=date.today(),
time=datetime.now().time()
)
if graph.last:
print "Getting graph data for '%s'" % exchange.name
db.session.add(graph)
else:
raise Exception
except Exception as err:
if not err.message:
err.message = 'Connection Error. Ticker API is down.'
print subject + ': ' + str(err.message)
if app.config.get('ENABLE_MAIL_NOTIFICATIONS', False):
send_async_email(subject, error_msg + str(err.message))
finally:
db.session.commit()
db.session.close()