Simple & compact Python Bitcoin ticker

Hi all,

Today, just fun.

I wrote a simple Bitcoin ticker. The concept is simple :

• using Python
• calling public rest service for Bitcoin rates
• using matplotlib
• updating in real time, 1 second interval just for fun

Using Python

It’s not breaking news, Python has a great success in data manipulation, exploration, visualization and science. Next time, I’ll show you some nice map rendering with Jupyter Notebooks, which I recommend for any data science project.

Here are the imports I used for this demonstration :

• numpy
• requests
• datetime
• time
• calendar
• matplotlib
• animation from matplotlib

Public Rest services for Bitcoin rates

You can easily find rest services providing data about Bitcoin. I chose to use this rest call : https://min-api.cryptocompare.com/data/price?fsym=BTC&tsyms=USD,EUR&e=Coinbase&extraParams=your_app_name

Pretty simple, this service returns some compact json data. In this use case, I will parse the json object and retrieve the USD rate only.

{"USD":8089.97,"EUR":6556.01}

Of course it is recommended to use data from different services, coming from different providers in order to have multiple Bitcoin rates and build something like an average.

The output

The output, with matplotlib, is a simple window displaying the graph and updating in real time. For this example, I chose a 1 second refresh rate (pretty useless but this was fun to see the high Bitcoin volatility).

Look at this accelerated gif, created from a record on April 18 2108, displaying the rates for approx 20 minutes. Sorry for the bad recording quality, I’ll do better soon.

The script

You can simply copy and paste this script, it will simply work. Just be sure to install the required packages. Just for information, I’m using Visual Studio Code for this use case.

import numpy as np  
import requests  
import datetime  
import time  
import calendar  
import matplotlib.pyplot as plt  
from matplotlib import animation  
   
x = np.arange(100000) # 100000 polling points  
usd = []  
  
fig, ax = plt.subplots()  
line, = ax.plot([], [], 'k-')  
ax.margins(0.05)  
   
def init():  
  line.set_data(x[:2],usd[:2])  
  return line,  
   
def animation(i):  
  time.sleep(1)  
  url = 'https://min-api.cryptocompare.com/data/price?fsym=BTC&tsyms=USD,EUR&e=Coinbase&extraParams=your_app_name'    
  r = requests.get(url)  
  r.json()  
  data = r.json()  
  usd.append(float(data['USD']))  
     
  win = 86400  
  imin = min(max(0, i - win), x.size - win)  
  xdata = x[imin:i]  
  ydata = usd[imin:i]  
  
  line.set_data(xdata, ydata)  
  ax.relim()  
  ax.autoscale()  
  return line,  
   
anim = animation.FuncAnimation(fig, animation, init_func=init, interval=25)  
plt.show()