geom_sina fails when index doesn't contain 0 #888
Description
As suggested in #221 , geom_sina fails (as of plotnine="0.14.1") when called on a dataframe whose index does not contain the 0 element:
# make up some random data
df_fails = pd.DataFrame({
'x': ['a','a','a','b','b','b'],
'y': [1, 2 ,3 ,4 ,5 ,6]
}, index=[1,2,3,4,5,6]) # note that 0 is NOT in the index
pn.ggplot(df_fails) + pn.aes(x='x', y='y') + pn.geom_sina()yields
---------------------------------------------------------------------------
KeyError Traceback (most recent call last)
File /opt/conda/lib/python3.11/site-packages/pandas/core/indexes/base.py:3805, in Index.get_loc(self, key)
3804 try:
-> 3805 return self._engine.get_loc(casted_key)
3806 except KeyError as err:
File index.pyx:167, in pandas._libs.index.IndexEngine.get_loc()
File index.pyx:196, in pandas._libs.index.IndexEngine.get_loc()
File pandas /_libs/hashtable_class_helper.pxi:2606] in pandas._libs.hashtable.Int64HashTable.get_item()
File pandas/_libs/hashtable_class_helper.pxi:2630, in pandas._libs.hashtable.Int64HashTable.get_item()
KeyError: 0
It traces back to this line
File /opt/conda/lib/python3.11/site-packages/plotnine/mapping/aes.py:647 in has_groups(data)
632 """
633 Check if data is grouped
634
(...)
643 If True, the data has groups.
644 """
645 # If any row in the group column is equal to NO_GROUP, then
646 # the data all of them are and the data has no groups
--> 647 return data.loc[0, "group"] != NO_GROUP
Unfortunately I don't have time to look at the code more closely, but clearly this hard indexing via data.loc[0, "group"] will fail whenever data doesn't have 0 in its index.
Current workaround
Just reset the index via df_fails = df_fails.reset_index(drop=True) as pointed out by @idavi-bcs in #221 (comment)