Make cell execution aware of previous cells

[egolep]

Maybe it is already possible or maybe it is not even planned or wanted, but I was wondering if there is a way to make different code cells aware of each other. For example, if my first code cell is:

@code python
a = 3
@end

and the second is:

@code python
print(a)
@end

The second cell, when executed, actually prints a = 3 instead of returnin an error saying that a does not exist.