DataSource.patch triggering TypeError: 'tuple' object does not support item assignment

Community Support
1

I have working code old older Bokeh/Python versions and am trying to update using Bokeh 2.2.3 and Python 3.8.

When I try to patch a DataSource i get the error:

TypeError: ‘tuple’ object does not support item assignment

Please see sample below…

ceokey = ‘CTX:David Reeves’
print(type(ds))
idx = sectorsource.data[‘ceo’].index(ceokey)

patches = {‘color’ : }
save_colour = sectorsource.data[‘color’][idx]

patches[‘color’].append((idx, ‘#471568’))
print(‘Patches:’,patches[‘color’])

ds.patch(patches)

This trips as follows:…

TypeError Traceback (most recent call last)
in
9 print(‘Patches:’,patches[‘color’])
10
—> 11 ds.patch(patches)

~/opt/anaconda3/lib/python3.8/site-packages/bokeh/models/sources.py in patch(self, patches, setter)
682 raise ValueError(“Invalid patch index: %s” % ind)
683
→ 684 self.data._patch(self.document, self, patches, setter)
685
686 class CDSView(Model):

~/opt/anaconda3/lib/python3.8/site-packages/bokeh/core/property/wrappers.py in _patch(self, doc, source, patches, setter)
461 for ind, value in patch:
462 if isinstance(ind, (int, slice)):
→ 463 self[name][ind] = value
464 else:
465 shape = self[name][ind[0]][tuple(ind[1:])].shape

TypeError: ‘tuple’ object does not support item assignment

Has anyone else seen this?

2

Just for giggles I made the following (very clunky) change to wrapper.py at line 462:

            if isinstance(ind, (int, slice)):
                as_list = list(self[name])
                #self[name][ind] = value
                as_list[ind] = value
                self[name] = tuple(as_list)

which seemed to fix the problem - I appreciate this may a very bad thing but just putting it out there…

3

The purpose of patch is to efficiently update without copying. If you want to patch, then your columns must be mutable (i.e. an array or list, not a tuple) If it ever worked with a tuple in the past, that was a bug.

4

Bryan,

The ColumnDataSournce is based ona dictionary of lists…

grp_list = [x for x in df['ceokey'].unique()]
xs = [df.loc[df['ceokey'] == i].Years for i in grp_list]
ys = [df.loc[df['ceokey'] == i].Relative for i in grp_list]
    
source = ColumnDataSource(data=dict(
    x = xs,
    y = ys,
    color = viridis(len(grp_list)),
    ceo = grp_list
    ))

Pretty standard stuff. The tach list is a single tuple (index, value) but that is used to do the patch and complies with the docs - am puzzled why it is now deemed to be updating a tuple rather than a lit item.

5

Bryan

I suspect I upgraded from older version of Bokeh along the way - viridis used to return a list, now returns a tuple.

If I listify the returned tuple before loading into the ColumnDataSource that should be fine.

6

@andrew.waites all the palettes were indeed converted to be tuples, in order to be able to discard a bunch of hacky code that mutable palettes had necessitated. I’d say it’s pretty unusual to set a palette as a CDS column value (palettes are usually inputs to colormappers) so listifying is the appropriate solution on he user side in those rare cases.