iterate over specific column up to a certain value in pandas

Question

A = pd.DataFrame({"type":['a','b','c', 'd','e'], "cost basis":[50, 40, 30, 20, 10], "value":[5, 25, 40, 10, 20]})

I am looking to iterate over the "value" column up to a certain value or sum in descending order. Let's say 50, whereas if the next number exceeds that value then the iteration would stop there.

Answer 1

Not sure that what you want but If I Understand correctly:

Try via cumsum():

out=A.loc[A['value'].cumsum().le(50)]

OR

If want in descending order then use sort_values()+cumsum():

out=A.loc[A.sort_values('value',ascending=False,ignore_index=True)['value'].cumsum().le(50)]