Python Quantitative Trading: How to Access Financial Market Data?

This article introduces how to use Python to call pre-packaged high-frequency data APIs. We’ll use Alltick’s tick data interface as an example. Here’s a sample code snippet.

Requesting Candlestick Data

import time
import requests
import json
 
# Extra headers
test_headers = {
    'Content-Type':'application/json'
}
 
'''
github：https://github.com/alltick/realtime-forex-crypto-stock-tick-finance-websocket-api

{"trace":"python_http_test1","data":{"code":"AAPL.US","kline_type":1,"kline_timestamp_end":0,"query_kline_num":2,"adjust_type":0}}
'''
test_url1 = 'https://quote.alltick.io/quote-stock-b-api/kline?token=e945d7d9-9e6e-4721-922a-7251a9d311d0-1678159756806&query=%7B%22trace%22%3A%22python_http_test1%22%2C%22data%22%3A%7B%22code%22%3A%22AAPL.US%22%2C%22kline_type%22%3A1%2C%22kline_timestamp_end%22%3A0%2C%22query_kline_num%22%3A2%2C%22adjust_type%22%3A0%7D%7D'
 
resp1 = requests.get(url=test_url1, headers=test_headers)
 
# Decoded text returned by the request
text1 = resp1.text
print(text1)

In the code above, we use the Apple stock (AAPL.US) as an example to request minute-level K-line data. To request other K-line types, pass the following values to kline_type:
1 – 1-minute, 2 – 5-minute, 3 – 15-minute, 4 – 30-minute,
5 – 1-hour, 6 – 2-hour, 7 – 4-hour, 8 – daily,
9 – weekly, 10 – monthly.

Requesting Latest Quote and Trade Data

import time
import requests
import json
 
# Extra headers
test_headers = {
    'Content-Type':'application/json'
}
 
'''
github：https://github.com/alltick/realtime-forex-crypto-stock-tick-finance-websocket-api

{"trace":"python_http_test2","data":{"symbol_list":[{"code": "700.HK"},{"code": "UNH.US"},{"code": "600416.SH"}]}}
'''
test_url1 = 'https://quote.alltick.io/quote-stock-b-api/trade-tick?token=e945d7d9-9e6e-4721-922a-7251a9d311d0-1678159756806&query=%7B%22trace%22%3A%22python_http_test2%22%2C%22data%22%3A%7B%22symbol_list%22%3A%5B%7B%22code%22%3A%20%22700.HK%22%7D%2C%7B%22code%22%3A%20%22UNH.US%22%7D%2C%7B%22code%22%3A%20%22600416.SH%22%7D%5D%7D%7D'
 
resp1 = requests.get(url=test_url1, headers=test_headers)
 
# Decoded text returned by the request
text1 = resp1.text
print(text1)

In this example, symbol_list can contain multiple symbols, including products from different markets.

Getting the Latest Order Book Quote Data

import time
import requests
import json
 
# Extra headers
test_headers = {
    'Content-Type':'application/json'
}
 
'''
github：https://github.com/alltick/realtime-forex-crypto-stock-tick-finance-websocket-api

{"trace":"python_http_test2","data":{"symbol_list":[{"code": "700.HK"},{"code": "UNH.US"},{"code": "600416.SH"}]}}
'''
test_url1 = 'https://quote.alltick.io/quote-stock-b-api/depth-tick?token=e945d7d9-9e6e-4721-922a-7251a9d311d0-1678159756806&query=%7B%22trace%22%3A%22python_http_test2%22%2C%22data%22%3A%7B%22symbol_list%22%3A%5B%7B%22code%22%3A%20%22700.HK%22%7D%2C%7B%22code%22%3A%20%22UNH.US%22%7D%2C%7B%22code%22%3A%20%22600416.SH%22%7D%5D%7D%7D'
 
resp1 = requests.get(url=test_url1, headers=test_headers)
 
# Decoded text returned by the request
text1 = resp1.text
print(text1)

Similarly, symbol_list supports multiple entries.

Subscribing to Real-Time Market Data via WebSocket

import json
import websocket    # pip install websocket-client
 
class Feed(object):
 
    def __init__(self):
        self.url = 'wss://quote.alltick.io/quote-stock-b-ws-api?token=e945d7d9-9e6e-4721-922a-7251a9d311d0-1678159756806'  
        self.ws = None
 
    def on_open(self, ws):
        """
        Callback object which is called at opening websocket.
        1 argument:
        @ ws: the WebSocketApp object
        """
        print('A new WebSocketApp is opened!')
 
        sub_param = {
            "cmd_id": 22002, 
            "seq_id": 123,
            "trace":"3baaa938-f92c-4a74-a228-fd49d5e2f8bc-1678419657806",
            "data":{
                "symbol_list":[
                    {
                        "code": "700.HK",
                        "depth_level": 5,
                    },
                    {
                        "code": "UNH.US",
                        "depth_level": 5,
                    },
                    {
                        "code": "600416.SH",
                        "depth_level": 5,
                    }
                ]
            }
        }
        
        sub_str = json.dumps(sub_param)
        ws.send(sub_str)
        print("depth quote are subscribed!")
 
    def on_data(self, ws, string, type, continue_flag):
        """
        4 argument.
        The 1st argument is this class object.
        The 2nd argument is utf-8 string which we get from the server.
        The 3rd argument is data type. ABNF.OPCODE_TEXT or ABNF.OPCODE_BINARY will be came.
        The 4th argument is continue flag. If 0, the data continue
        """
 
    def on_message(self, ws, message):
        """
        Callback object which is called when received data.
        2 arguments:
        @ ws: the WebSocketApp object
        @ message: utf-8 data received from the server
        """
        result = eval(message)
        print(result)
 
    def on_error(self, ws, error):
        """
        Callback object which is called when got an error.
        2 arguments:
        @ ws: the WebSocketApp object
        @ error: exception object
        """
        print(error)
 
    def on_close(self, ws, close_status_code, close_msg):
        """
        Callback object which is called when the connection is closed.
        2 arguments:
        @ ws: the WebSocketApp object
        @ close_status_code
        @ close_msg
        """
        print('The connection is closed!')
 
    def start(self):
        self.ws = websocket.WebSocketApp(
            self.url,
            on_open=self.on_open,
            on_message=self.on_message,
            on_data=self.on_data,
            on_error=self.on_error,
            on_close=self.on_close,
        )
        self.ws.run_forever()
 
 
if __name__ == "__main__":
    feed = Feed()
    feed.start()