The docstring of DataFrame.isetitem (https://pandas.pydata.org/docs/reference/api/pandas.DataFrame.isetitem.html) has the following quote:
Unlike
frame.iloc[:, i] = value,frame.isetitem(loc, value)will never try to set the values in place, but will always insert a new array.
But the docstring is actually confusing here, because it is an inplace method in the sense that it is updating the object inplace (and not returning a new object like most methods). It's only not inplace in the sense that it will not update values inplace.
Originally posted by @jorisvandenbossche in https://github.com/pandas-dev/pandas/issues/51296#issuecomment-1425998426
Comment From: jorisvandenbossche
We should also fix the formatting in that docstring to properly show the inline code snippets as code.
Comment From: loicdiridollou
I did a few experiments on my side to better understand the behavior and this is how we could rephrase it:
frame.isetimtem(loc, value)is an in-place method as it will modify the frame in place (not returning a new object) but it will not update the values of the column itself, it will instead insert a new array.
I will address the code snippets in the meantime. Let me know if you agree with the rephrasing above, I can make another proposal if needed.
Comment From: loicdiridollou
take