Update data point labels in bokeh plot - matplotlib

Question

I use bokeh in an ipython notebook and would like to have a button next to a plot to switch on or off labels of the data points. I found a solution using IPython.html.widgets.interact, but this solution resets the plot for each update including zooming and padding
This is the minimal working code example:
from numpy.random import random
from bokeh.plotting import figure, show, output_notebook
from IPython.html.widgets import interact
def plot(label_flag):
p = figure()
N = 10
x = random(N)+2
y = random(N)+2
labels = range(N)
p.scatter(x, y)
if label_flag:
pass
p.text(x, y, labels)
output_notebook()
show(p)
interact(plot, label_flag=True)
p.s. If there is an easy way to do this in matplotlib I would also switch back again.

Answer 1

By using bokeh.models.ColumnDataSource to store and change the plot's data I was able to achieve what I wanted.
One caveat is, that I found no way to make it work w/o refresh w/o calling output_notebook twice in two different cells. If I remove one of the two output_notebook calls the gui of the tools-button looks breaks or changing a setting also results in a reset of the plot.
from numpy.random import random
from bokeh.plotting import figure, show, output_notebook
from IPython.html.widgets import interact
from bokeh.models import ColumnDataSource
output_notebook()
## <-- new cell -->
p = figure()
N = 10
x_data = random(N)+2
y_data = random(N)+2
labels = range(N)
source = ColumnDataSource(
data={
'x':x_data,
'y':y_data,
'desc':labels
}
)
p.scatter('x', 'y', source=source)
p.text('x', 'y', 'desc', source=source)
output_notebook()
def update_plot(label_flag=True):
if label_flag:
source.data['desc'] = range(N)
else:
source.data['desc'] = ['']*N
show(p)
interact(update_plot, label_flag=True)