def apply_multiindex_or_single_index(self, result): if len(result) == 0: final_result = DataFrame() for col in result.columns: if col not in self._by: final_result[col] = result[col] if len(self._by) == 1 or len(final_result.columns) == 0: dtype = 'float64' if len(self._by) == 1 else 'object' name = self._by[0] if len(self._by) == 1 else None from cudf.dataframe.index import GenericIndex index = GenericIndex(Series([], dtype=dtype)) index.name = name final_result.index = index else: mi = MultiIndex(source_data=result[self._by]) mi.names = self._by final_result.index = mi if len(final_result.columns) == 1 and hasattr(self, "_gotattr"): final_series = Series([], name=final_result.columns[0]) final_series.index = final_result.index return final_series return final_result if len(self._by) == 1: from cudf.dataframe import index idx = index.as_index(result[self._by[0]]) idx.name = self._by[0] result = result.drop(idx.name) if idx.name == self._LEVEL_0_INDEX_NAME: idx.name = self._original_index_name result = result.set_index(idx) return result else: multi_index = MultiIndex(source_data=result[self._by]) final_result = DataFrame() for col in result.columns: if col not in self._by: final_result[col] = result[col] if len(final_result.columns) == 1 and hasattr(self, "_gotattr"): final_series = Series(final_result[final_result.columns[0]]) final_series.name = final_result.columns[0] final_series.index = multi_index return final_series return final_result.set_index(multi_index)
def _getitem_tuple_arg(self, arg): from cudf import MultiIndex from cudf.dataframe.dataframe import DataFrame from cudf.dataframe.dataframe import Series from cudf.dataframe.index import as_index # Iloc Step 1: # Gather the columns specified by the second tuple arg columns = self._get_column_selection(arg[1]) if isinstance(self._df.columns, MultiIndex): columns_df = self._df.columns._get_column_major(self._df, arg[1]) if ( len(columns_df) == 0 and len(columns_df.columns) == 0 and not isinstance(arg[0], slice) ): result = Series([], name=arg[0]) result._index = columns_df.columns.copy(deep=False) return result else: if isinstance(arg[0], slice): columns_df = DataFrame() for col in columns: columns_df.add_column(name=col, data=self._df[col]) columns_df._index = self._df._index else: columns_df = self._df._columns_view(columns) # Iloc Step 2: # Gather the rows specified by the first tuple arg if isinstance(columns_df.index, MultiIndex): df = columns_df.index._get_row_major(columns_df, arg[0]) if (len(df) == 1 and len(columns_df) >= 1) and not ( isinstance(arg[0], slice) or isinstance(arg[1], slice) ): # Pandas returns a numpy scalar in this case return df[0] if self._can_downcast_to_series(df, arg): return self._downcast_to_series(df, arg) return df else: df = DataFrame() for key, col in columns_df._cols.items(): df[key] = col.iloc[arg[0]] df.columns = columns_df.columns # Iloc Step 3: # Reindex if df.shape[0] == 1: # we have a single row without an index if isinstance(arg[0], slice): start = arg[0].start if start is None: start = 0 df.index = as_index(self._df.index[start]) else: df.index = as_index(self._df.index[arg[0]]) # Iloc Step 4: # Downcast if self._can_downcast_to_series(df, arg): if isinstance(df.columns, MultiIndex): if len(df) > 0 and not ( isinstance(arg[0], slice) or isinstance(arg[1], slice) ): return list(df._cols.values())[0][0] elif df.shape[1] > 1: result = self._downcast_to_series(df, arg) result.index = df.columns return result elif not isinstance(arg[0], slice): result_series = list(df._cols.values())[0] result_series.index = df.columns result_series.name = arg[0] return result_series else: return list(df._cols.values())[0] return self._downcast_to_series(df, arg) if df.shape[0] == 0 and df.shape[1] == 0: from cudf.dataframe.index import RangeIndex slice_len = arg[0].stop or len(self._df) start, stop, step = arg[0].indices(slice_len) df._index = RangeIndex(start, stop) return df
def apply_multiindex_or_single_index(self, result): if len(result) == 0: final_result = DataFrame() for col in result.columns: if col not in self._by: final_result[col] = result[col] if len(self._by) == 1 or len(final_result.columns) == 0: dtype = 'float64' if len(self._by) == 1 else 'object' name = self._by[0] if len(self._by) == 1 else None from cudf.dataframe.index import GenericIndex index = GenericIndex(Series([], dtype=dtype)) index.name = name final_result.index = index else: levels = [] codes = [] names = [] for by in self._by: levels.append([]) codes.append([]) names.append(by) mi = MultiIndex(levels, codes) mi.names = names final_result.index = mi if len(final_result.columns) == 1 and hasattr(self, "_gotattr"): final_series = Series([], name=final_result.columns[0]) final_series.index = final_result.index return final_series return final_result if len(self._by) == 1: from cudf.dataframe import index idx = index.as_index(result[self._by[0]]) idx.name = self._by[0] result = result.drop(idx.name) if idx.name == self._LEVEL_0_INDEX_NAME: idx.name = self._original_index_name result = result.set_index(idx) return result else: levels = [] codes = DataFrame() names = [] # Note: This is an O(N^2) solution using gpu masking # to compute new codes for the MultiIndex. There may be # a faster solution that could be executed on gpu at the same # time the groupby is calculated. for by in self._by: level = result[by].unique() replaced = result[by].replace(level, range(len(level))) levels.append(level) codes[by] = Series(replaced, dtype="int32") names.append(by) multi_index = MultiIndex(levels=levels, codes=codes, names=names) final_result = DataFrame() for col in result.columns: if col not in self._by: final_result[col] = result[col] if len(final_result.columns) == 1 and hasattr(self, "_gotattr"): final_series = Series(final_result[final_result.columns[0]]) final_series.name = final_result.columns[0] final_series.index = multi_index return final_series return final_result.set_index(multi_index)
def _get_row_major(self, df, row_tuple): slice_access = False if isinstance(row_tuple[0], numbers.Number): valid_indices = row_tuple[0] elif isinstance(row_tuple[0], slice): # 1. empty slice compute if row_tuple[0].stop == 0: valid_indices = [] else: slice_access = True start = row_tuple[0].start or 0 stop = row_tuple[0].stop or len(df) step = row_tuple[0].step or 1 valid_indices = cudautils.arange(start, stop, step) else: valid_indices = self._compute_validity_mask(df, row_tuple) from cudf import Series result = df.take(Series(valid_indices)) # Build new index - INDEX based MultiIndex # --------------- from cudf import DataFrame out_index = DataFrame() # Select the last n-k columns where n is the number of source # levels and k is the length of the indexing tuple size = 0 if not isinstance(row_tuple[0], (numbers.Number, slice)): size = len(row_tuple) for k in range(size, len(df.index.levels)): out_index.add_column(df.index.names[k], df.index.codes[df.index.codes.columns[k]]) # If there's only one column remaining in the output index, convert # it into an Index and name the final index values according # to the proper codes. if len(out_index.columns) == 1: out_index = [] for val in result.index.codes[result.index.codes.columns[len(result.index.codes.columns)-1]]: # noqa: E501 out_index.append(result.index.levels[ len(result.index.codes.columns)-1][val]) out_index = as_index(out_index) out_index.name = result.index.names[len(result.index.names)-1] result.index = out_index else: if len(result) == 1 and size == 0 and slice_access is False: # If the final result is one row and it was not mapped into # directly result = result.T result = result[result.columns[0]] # convert to Series series_name = [] for idx, code in enumerate(result.columns.codes): series_name.append(result.columns.levels[idx][ result.columns.codes[code][0]]) result = Series(list(result._cols.values())[0], name=series_name) result.name = tuple(series_name) elif(len(out_index.columns)) > 0: # Otherwise pop the leftmost levels, names, and codes from the # source index until it has the correct number of columns (n-k) result.reset_index(drop=True) result.index = result.index._popn(size) return result