X = data.iloc[:, :-1]

As an AI language model, I do not have access to the specific dataset that you are working with, so I can only provide a general explanation of this line of code.

The code "X = data.iloc[:, :-1]" is used to assign a subset of a dataset to a variable named "X".

The "data" variable is assumed to be a pandas DataFrame, which is a tabular data structure that can hold data of different types in columns.

The "iloc" method is used to select rows and columns of the DataFrame by their integer position.

The first parameter, ":", specifies that we want to select all rows of the DataFrame.

The second parameter, ":-1", specifies that we want to select all columns of the DataFrame except for the last one. The "-1" index indicates the last column, so ":-1" means "all columns up to but not including the last one".

Therefore, the "X" variable will contain all the rows of the DataFrame except for the last column. This is often done in machine learning tasks where the last column represents the target variable or output that we want to predict, and the remaining columns represent the input features.