Checking function of GPIO channels

gpio_function(channel)

Shows the function of a GPIO channel.
For example:

import RPi.GPIO as GPIO

GPIO.setmode(GPIO.BOARD)
func = GPIO.gpio_function(pin)

will return a value from:
GPIO.IN, GPIO.OUT, GPIO.SPI, GPIO.I2C, GPIO.HARD_PWM, GPIO.SERIAL, GPIO.UNKNOWN