boolean indexing that can produce a view to a large pandas dataframe?

Question

Got a large dataframe that I want to take slices of (according to multiple boolean criteria), and then modify the entries in those slices in order to change the original datafra

Answer 1

The pandas docs have a section on Returning a view versus a copy:

The rules about when a view on the data is returned are entirely dependent on NumPy. Whenever an array of labels or a boolean vector are involved in the indexing operation, the result will be a copy. With single label / scalar indexing and slicing, e.g. df.ix[3:6] or df.ix[:, 'A'], a view will be returned.