Why are these two variables synced together

Asked May 21 '16 at 16:52

Active May 21 '16 at 16:55

Viewed 38 times

I wrote the following code:

grid = [[0,0,0,0,0],[0,0,0,0,0]]

grid2 = [[1,1,1,1,1],[1,1,1,1,1]]

grid2 = grid

grid2[0][0] = 5

print(grid2)
print(grid)

And this is the output:

[[5, 0, 0, 0, 0], [0, 0, 0, 0, 0]]
[[5, 0, 0, 0, 0], [0, 0, 0, 0, 0]]

Why does the variable grid also get 5 in its output? These are two separate variables and I'm only changing one? Is there anyway to not have them synced?

edited May 21 '16 at 16:55

Bono

4,757
6
48
77

asked May 21 '16 at 16:52

The Odd Fox

Sounds like you could use [a quick guide to the semantics of Python variables and assignment](http://nedbatchelder.com/text/names.html). – user2357112 May 21 '16 at 16:54
They stop being separate "variables" when you bind the same object to both. – Ignacio Vazquez-Abrams May 21 '16 at 16:55
Grid2 is a *reference* to the other Grid – OneCricketeer May 21 '16 at 16:58

Why are these two variables synced together

0 Answers0