Reading data from Si7021 sensor on Linux using Python

#!/usr/bin/env python3
import smbus

if __name__ == '__main__':
    bus = smbus.SMBus(0) # assuming your sensor is /dev/i2c-0
    addr = 0x40

    # read temperature (in celsius)
    b = bus.read_i2c_block_data(addr, 0xE3, 2)
    temp = 175.72 * (b[0] << 8 | b[1]) / 65536.0 - 46.85

    # read humidity (percentage)
    b = bus.read_i2c_block_data(addr, 0xE5, 2)
    humidity = 125.0 * (b[0] << 8 | b[1]) / 65536.0 - 6.0

    print("humidity: " + str(humidity))
    print("temp: " + str(temp))