Local streaming data to Dash/python

Dash Python
1

Hi,

I’m currently getting data from online API to a local database and using it to build a dash board.
However, the data on the dash board is no updating even thougth the local database is getting new rows every minute.

Can anyone advise how to fix this?

Also, I tried to get streaming API tokens from plotly but the command below returns blank list:

stream_ids = tls.get_credentials_file()[‘stream_ids’]
print stream_ids

The code i used to gernerate the database is shown below

import time
import datetime
import requests
import sqlite3
import plotly
import plotly.plotly as py
import plotly.graph_objs as go
import numpy as np
import dash
import dash_core_components as dcc
import dash_html_components as html


def historical_data():
	response_his = requests.get("https://min-api.cryptocompare.com/data/histominute?fsym=BTC&tsym=USD&limit=2000")
	a = response_his.json()
	his = []
	for i in range(len(a[u'Data'])):
		data = []
		data.append(time.strftime("%D %H:%M", time.localtime(int(a[u'Data'][i][u'time']))))
		data.append(a[u'Data'][i][u'close'])
		his.append(data)
	return his
def current():
	response_current = requests.get("https://min-api.cryptocompare.com/data/price?fsym=BTC&tsyms=USD,EUR")
	current = response_current.json()
	return current
a = historical_data()
conn = sqlite3.connect('crypto.db')
c = conn.cursor()
#c.execute('DROP TABLE historical_data')
c.execute('CREATE TABLE historical_data(time TEXT, price FLOAT)')
c.executemany('INSERT INTO historical_data VALUES(?,?)', a)
conn.commit()
#conn.close()
i = 0
while i <100:
	#conn = sqlite3.connect('crypto.db')
	#c = conn.cursor()
	a_0 = historical_data()
	if a[len(a)-1][0] != a_0[len(a_0)-1][0]:
		a.append(a_0[len(a_0)-1])
		c.execute('INSERT INTO historical_data VALUES(?,?)', a[len(a)-1])
	b = current()
	i = i+1
	time.sleep(60)
	c.execute('SELECT MAX(time), price FROM historical_data')
	print c.fetchall()
	c.execute('SELECT COUNT(*) FROM historical_data')
	print c.fetchall()
	c.execute('SELECT * FROM historical_data')
	table = c.fetchall()
	print len(table)
	conn.commit()
conn.close()
2

Hey
The best way to do this is to use an update function See this Documentation. There is the interval=1*1000 that sets the time your code checks the files for changes, then there is the n-intervals = 0. Run the example on this page and see how it works. you can set a longer refresh interval if your net coinnection is weak.