blink.py

from time import sleep
from gpiozero import LED

led = LED(17)

while True:
    led.toggle()
    sleep(0.250)

gpio_led.sh

pi@raspberrypi:~ $ gpio mode 0 out
pi@raspberrypi:~ $ gpio write 0 1
pi@raspberrypi:~ $ gpio write 0 0

gpio_led_py.sh

pi@raspberrypi:~ $ python
Python 2.7.9 (default, Mar  8 2015, 00:52:26) 
[GCC 4.9.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> from gpiozero import LED
>>> led = LED(17)
>>> led.on()
>>> led.off()