Python • Showing connected GPIO pins via I2C

Code:

from flask import Flask, render_templatefrom RPLCD.i2c import CharLCDimport RPi.GPIO as GPIOimport smbusimport timeimport jsonapp = Flask(__name__)lcd = CharLCD(i2c_expander='PCF8574', address=0x27, port=1, cols=16, rows=2, dotsize=8)lcd.clear()lcd.write_string('testing')# Set up GPIOGPIO.setmode(GPIO.BCM)total_pins = 26  connected_pins = []# Set up I2Ci2c = smbus.SMBus(1)  DISPLAY_ADDRESS = 0x27  DISPLAY_WIDTH = 16# Function to read GPIO pin statusdef read_gpio(pin):    GPIO.setup(pin, GPIO.IN, pull_up_down=GPIO.PUD_UP)    return GPIO.input(pin)@app.route('/')def index():    global connected_pins    connected_pins = []        for pin in range(total_pins):        if not read_gpio(pin):            connected_pins.append(pin)    display_pins(connected_pins)    return render_template('index.html', connected_pins=connected_pins)# Route for updating pin status via AJAX@app.route('/update_pins')def update_pins():    global connected_pins    connected_pins = []        for pin in range(total_pins):        if not read_gpio(pin):            connected_pins.append(pin)    display_pins(connected_pins)    return json.dumps({'connected_pins': connected_pins})if __name__ == '__main__':    app.run(debug=True, host='0.0.0.0')