API should accept python 'range' type.

[alshan]

This code should work:

data = dict(
    c = list(range(10)),
    x = range(10),
    y = range(10)
)

ggplot(data) + geom_point(aes('x', 'y', col='c'))

Currently error:

The value of data variable [x] must be a list but was String