Correct Method for Data Capture and Filtering

Question

Below is my python code for fetching data from ADS1263. The ic has been configured properly and i am getting the data. I want to filter the data on the fly or you can say fetch one data and filter it and print it on the screen. I am trying to apply low pass butter filter but i am not getting any constant results.

Can somebody guide me how to apply filter to the new data, one data at a time ?

import time
import ADS1263
import RPi.GPIO as GPIO
import statistics
from scipy.signal import butter, sosfiltfilt
from scipy.signal import firwin, filtfilt


fs = 20.0  # Sampling frequency (Hz)
fc = 0.05  # Cutoff frequency (Hz)

order1 = 3       # You may need a large order for such a low cutoff

fir_coef = firwin(order1+1, fc/(fs/2), window='hamming')

order = 5

sos = butter(order, fc/(fs/2), btype='low', output='sos')

my_index = 0
my_list  = [0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]

try:
    ADC = ADS1263.ADS1263()
    
    #Config ADC for Differential Measurement
    ADC.ADS_1263_Get_Registers()
   
    #Start ADC
    ADC.ADS1263_WriteCmd(0x08)    

    while(1):
        
        ADC.ADS1263_WaitDRDY()       
        value = ADC.ADS1263_Read_ADC_Data()

        if(value & 0x80000000):
            value |= 0xff000000
        
        value1 = (value * (2.0 * 5.080) ) / ( 32 * 4294967296.0 )  
        
        value1 = value1 * 1000;     
        
        if my_index < 19:
            my_list[my_index] = value1
            my_index = my_index + 1
        else:            
            my_list[my_index] = value1     
                                 
            filtered_signal = sosfiltfilt(sos, my_list)  
    
            _mean = filtered_signal[-1]            
            print("mV = %0.5lf" %(_mean))            
            my_index = 0            
            for i in range(19):
                my_list[i] = my_list[i+1]


    ADC.ADS1263_Exit()

except IOError as e:
    print(e)
   
except KeyboardInterrupt:
    print("ctrl + c:")
    print("Program end")
    ADC.ADS1263_Exit()
    exit()