Whats happening here?

Question

z=[0 for i in range(3)]
print(z) # [0,0,0]
x=[z for i in range(3)]
print(x) #[[0,0,0],[0,0,0],[0,0,0]]
x[1][1]=7
print(x) #[[0,7,0],[0,7,0],[0,7,0]]

Can someone explain what's happening here?

imagine `x` as `[z, z, z]`. What happens when you alter `z`? — Aykhan Hagverdili, Dec 31 '18 at 08:59

score 0 · Accepted Answer · answered Dec 31 '18 at 08:44

0

x=[z for i in range(3)]

In this line, it is the reference of z that is repeated as each element in the list x

So, when you modify one sub-list (or element of x), all the other elements get modified as all are just references.

answered Dec 31 '18 at 08:44

Jay

1 Answers1