Bubble chart broken in 0.26/0.29/0.31 when the bubble size's metric is already used

[elukey]

Make sure these boxes are checked before submitting your issue - thank you!

• I have checked the superset logs for python stacktraces and included it here as text if there are any.
• I have reproduced the issue with at least the latest released version of superset.
• I have checked the issue tracker for the same issue and I haven't found one similar.

Superset version

0.29/0.31

A Bubble chart using in its Query section a function(metric) already used elsewhere (like in either X or Y axe) ends up in the following error(s):

Traceback (most recent call last):
  File "/srv/deployment/analytics/superset/venv/lib/python3.7/site-packages/pandas/core/indexes/base.py", line 3078, in get_loc
    return self._engine.get_loc(key)
  File "pandas/_libs/index.pyx", line 140, in pandas._libs.index.IndexEngine.get_loc
  File "pandas/_libs/index.pyx", line 157, in pandas._libs.index.IndexEngine.get_loc
  File "pandas/_libs/index.pyx", line 183, in pandas._libs.index.IndexEngine._get_loc_duplicates
  File "pandas/_libs/index.pyx", line 200, in pandas._libs.index.IndexEngine._maybe_get_bool_indexer
KeyError: 'x'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/srv/deployment/analytics/superset/venv/lib/python3.7/site-packages/pandas/core/internals.py", line 4243, in set
    loc = self.items.get_loc(item)
  File "/srv/deployment/analytics/superset/venv/lib/python3.7/site-packages/pandas/core/indexes/base.py", line 3080, in get_loc
    return self._engine.get_loc(self._maybe_cast_indexer(key))
  File "pandas/_libs/index.pyx", line 140, in pandas._libs.index.IndexEngine.get_loc
  File "pandas/_libs/index.pyx", line 157, in pandas._libs.index.IndexEngine.get_loc
  File "pandas/_libs/index.pyx", line 183, in pandas._libs.index.IndexEngine._get_loc_duplicates
  File "pandas/_libs/index.pyx", line 200, in pandas._libs.index.IndexEngine._maybe_get_bool_indexer
KeyError: 'x'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/srv/deployment/analytics/superset/venv/lib/python3.7/site-packages/superset/views/base.py", line 114, in wraps
    return f(self, *args, **kwargs)
  File "/srv/deployment/analytics/superset/venv/lib/python3.7/site-packages/superset/views/core.py", line 1229, in explore_json
    samples=samples,
  File "/srv/deployment/analytics/superset/venv/lib/python3.7/site-packages/superset/views/core.py", line 1160, in generate_json
    payload = viz_obj.get_payload()
  File "/srv/deployment/analytics/superset/venv/lib/python3.7/site-packages/superset/viz.py", line 375, in get_payload
    payload['data'] = self.get_data(df)
  File "/srv/deployment/analytics/superset/venv/lib/python3.7/site-packages/superset/viz.py", line 967, in get_data
    df['x'] = df[[utils.get_metric_name(self.x_metric)]]
  File "/srv/deployment/analytics/superset/venv/lib/python3.7/site-packages/pandas/core/frame.py", line 3119, in __setitem__
    self._set_item(key, value)
  File "/srv/deployment/analytics/superset/venv/lib/python3.7/site-packages/pandas/core/frame.py", line 3195, in _set_item
    NDFrame._set_item(self, key, value)
  File "/srv/deployment/analytics/superset/venv/lib/python3.7/site-packages/pandas/core/generic.py", line 2600, in _set_item
    self._data.set(key, value)
  File "/srv/deployment/analytics/superset/venv/lib/python3.7/site-packages/pandas/core/internals.py", line 4246, in set
    self.insert(len(self.items), item, value)
  File "/srv/deployment/analytics/superset/venv/lib/python3.7/site-packages/pandas/core/internals.py", line 4347, in insert
    placement=slice(loc, loc + 1))
  File "/srv/deployment/analytics/superset/venv/lib/python3.7/site-packages/pandas/core/internals.py", line 3205, in make_block
    return klass(values, ndim=ndim, placement=placement)
  File "/srv/deployment/analytics/superset/venv/lib/python3.7/site-packages/pandas/core/internals.py", line 125, in __init__
    '{mgr}'.format(val=len(self.values), mgr=len(self.mgr_locs)))
ValueError: Wrong number of items passed 2, placement implies 1

I wasn't able to track down the origin of the problem. Looks similar to #7006, but after some tests I can see the same issue on 0.26, so probably unrelated to the pandas bump happened in 0.29+.

To be precise: in the above example, If I don't reuse the metric in the Bubble size (but I choose any other available) everything works fine.

[elukey]

I confirm that it fixes the problem, thanks! It would be great if this could be backported to 0.29/0.31, otherwise 0.32 will be fine.

[elukey]

@mistercrunch Would it be possible to get this backported to release--0.31?

[elukey]

This only needs a backport of the commit to the release--0.31 branch and then we can close.