如何使用变量列表循环 function？

Question

I have a function that prints OHLCV data for stock prices from a websocket. It works but I have to copy it for each variable (Var1 to Var14) to get each individual stock data. How would I automate this process given that I have list:

varlist = [var1, var2, var3...var14]

and my code is:

def process_messages_for_var1(msg):
    if msg['e'] == 'error':
        print(msg['m'])
   # If message is a trade, print the OHLC data
    else:
    # Convert time into understandable structure
    transactiontime = msg['k']['T'] / 1000
    transactiontime = datetime.fromtimestamp(transactiontime).strftime('%d %b %Y %H:%M:%S')
    # Process this message once websocket starts
    print("{} - {} - Interval {} - Open: {} - Close: {} - High: {} - Low: {} - Volume: {}".
          format(transactiontime,msg['s'],msg['k']['i'],msg['k']['o'],msg['k']['c'],msg['k']['h'],msg['k']['l'],msg['k']['v']))
    # Also, put information into an array
    kline_array_msg = "{},{},{},{},{},{}".format(
        msg['k']['T'],msg['k']['o'],msg['k']['c'],msg['k']['h'],msg['k']['l'],msg['k']['v'])         
# Insert at first position
    kline_array_dct[var1].insert(0, kline_array_msg)
    if (len(kline_array_dct[var1]) > window): 
        # Remove last message when res_array size is > of FIXED_SIZE
        del kline_array_dct[var1][-1]

I'm hoping to get the following result (notice how function name also changes):

def process_messages_for_var2(msg):
   if msg['e'] == 'error':
       print(msg['m'])
   # If message is a trade, print the OHLC data
   else:
   # Convert time into understandable structure
   transactiontime = msg['k']['T'] / 1000
   transactiontime = datetime.fromtimestamp(transactiontime).strftime('%d %b %Y %H:%M:%S')
   # Process this message once websocket starts
   print("{} - {} - Interval {} - Open: {} - Close: {} - High: {} - Low: {} - Volume: {}".
          format(transactiontime,msg['s'],msg['k']['i'],msg['k']['o'],msg['k']['c'],msg['k']['h'],msg['k']['l'],msg['k']['v']))
    # Also, put information into an array
    kline_array_msg = "{},{},{},{},{},{}".format(
        msg['k']['T'],msg['k']['o'],msg['k']['c'],msg['k']['h'],msg['k']['l'],msg['k']['v'])         
# Insert at first position
    kline_array_dct[var2].insert(0, kline_array_msg)
    if (len(kline_array_dct[var2]) > window): 
        # Remove last message when res_array size is > of FIXED_SIZE
        del kline_array_dct[var2][-1]

Answer 1

You can adjust the function so that it takes one of the var s as an argument. Ie,

def process_messages(msg, var):
    ...

    kline_array_dct[var].insert(0, kline_array_msg)
    if (len(kline_array_dct[var]) > window): 
        # Remove last message when res_array size is > of FIXED_SIZE
        del kline_array_dct[var][-1]

Answer 2

If the processes are generally the same, just define one of them, and give it more arguments:

def process_messages(msg, var)

Then, you can adjust your process code to run through each var when you call it. You can do this by removing the numbered vars in the process code:

if msg['e'] == 'error':
   print(msg['m'])
   # If message is a trade, print the OHLC data
   else:
   # Convert time into understandable structure
   transactiontime = msg['k']['T'] / 1000
   transactiontime = datetime.fromtimestamp(transactiontime).strftime('%d %b %Y %H:%M:%S')
   # Process this message once websocket starts
   print("{} - {} - Interval {} - Open: {} - Close: {} - High: {} - Low: {} - Volume: {}".
          format(transactiontime,msg['s'],msg['k']['i'],msg['k']['o'],msg['k']['c'],msg['k']['h'],msg['k']['l'],msg['k']['v']))
    # Also, put information into an array
    kline_array_msg = "{},{},{},{},{},{}".format(
        msg['k']['T'],msg['k']['o'],msg['k']['c'],msg['k']['h'],msg['k']['l'],msg['k']['v'])         
# Insert at first position
    kline_array_dct[var].insert(0, kline_array_msg)
    if (len(kline_array_dct[var]) > window): 
        # Remove last message when res_array size is > of FIXED_SIZE
        del kline_array_dct[var][-1]

Then, create a simple for loop to call the process for each var in the list:

for var in varList:
    process_messages("msg", var)

The for loop will call the process for each var in the list.