Human: Summing across rows of Pandas Dataframe Assistant: 
Here is some code to sum the column `positions` along the  other columns `stock`, `same1`, `same2` in a pandas data frame `df`

df.groupby(['stock', 'same1', 'same2'], as_index=False)['positions'].sum()

#Warning: this code generation is experimental. Please inspect the code for any bugs before executing.