Why x!=y?

Question

x=[[0,0],[0,0]]
x[0][0]=5
y=[[0]*2]*2
y[0][0]=5
print(x==y)

#but output = False why can anyone tell me.

Answer 1

This is because of the fact that list y is not evaluated until the compilation of print statement.

Therefore, y[0][0] = 5
changes y as:
y = [[5, 0]] * 2

# which makes the difference ;)
P.S: you can try printing x and y seperately to see the fact in action!

Answer 2

@Blue: YES, the list is evaluated before the print function call. And it is not a statement either.
And finally, we get y = [[5,0],[5,0]] and not y = [[5,5],[5,5]]