### Sage behaves different locally vs. in cloud.sagemath.com

I was trying to plot some complex numbers, with the following code:

```
data1 = []
data2 = []
for i in range(15):
theta = 2*pi*i/15.0
v = e^(I*theta) + 3
w = e^(I*theta) + 3*I
data1.append(v)
data2.append(w)
list_plot(data1)
# list_plot(data2)
```

But for some reason, an error occurs when I try to plot data2. (But no error for data1...)

The traceback for the error is the following:

Traceback (most recent call last): data1.append(v)
File "", line 1, in <module>

File "/private/var/folders/9r/5rcwvsmn0jxb2452tv5csp1m0000gn/T/tmp4032QP/___code___.py", line 12, in <module>
exec compile(u'list_plot(data2)
File "", line 1, in <module>

File "/Applications/Sage-6.3.app/Contents/Resources/sage/local/lib/python2.7/site-packages/sage/misc/decorators.py", line 550, in wrapper
return func(*args, **options)
File "/Applications/Sage-6.3.app/Contents/Resources/sage/local/lib/python2.7/site-packages/sage/plot/plot.py", line 1888, in list_plot
data = [(z.real(), z.imag()) for z in [CC(z[1]) for z in data]]
TypeError: 'sage.symbolic.expression.Expression' object does not support indexing

The error doesn't appear if I try the putting the code on cloud.sagemath.com, which seems to imply that sage is not working properly on my computer? If so, how might I fix this?