Descriptive

DataFrame.approx_n_unique()	Approximate count of unique values.
DataFrame.approx_unique()	Approximate count of unique values.
DataFrame.describe([percentiles])	Summary statistics for a DataFrame.
DataFrame.glimpse()	Return a dense preview of the DataFrame.
DataFrame.estimated_size([unit])	Return an estimation of the total (heap) allocated size of the DataFrame.
DataFrame.is_duplicated()	Get a mask of all duplicated rows in this DataFrame.
DataFrame.is_empty()	Check if the dataframe is empty.
DataFrame.is_unique()	Get a mask of all unique rows in this DataFrame.
DataFrame.n_chunks()	Get number of chunks used by the ChunkedArrays of this DataFrame.
DataFrame.n_unique([subset])	Return the number of unique rows, or the number of unique row-subsets.
DataFrame.null_count()	Create a new DataFrame that shows the null counts per column.