random.seed(): What does it do?

Question

I am a bit confused on what random.seed() does in Python. For example, why does the below trials do what they do (consistently)?

>>> i         


        

Answer 1

All the other answers don't seem to explain the use of random.seed(). Here is a simple example (source):

import random
random.seed( 3 )
print "Random number with seed 3 : ", random.random() #will generate a random number 
#if you want to use the same random number once again in your program
random.seed( 3 )
random.random()   # same random number as before