def apply_multicolumn(self, result, aggs):
# multicolumn only applies with multiple aggs and multiple groupby keys
if len(aggs) == 1 or len(self._by) == 1:
# unprefix columns
new_cols = []
for c in result.columns:
if len(self._by) == 1 and len(result) != 0:
new_col = c.split('_')[0] # sum_z-> (sum, z)
else:
new_col = c.split('_')[1] # sum_z-> (sum, z)
new_cols.append(new_col)
result.columns = new_cols
else:
# reorder our columns to match pandas
if len(self._val_columns) > 1:
col_dfs = [DataFrame() for col in self._val_columns]
for agg in aggs:
for idx, col in enumerate(self._val_columns):
col_dfs[idx][agg + '_' + col] = result[agg + '_' + col]
idx = result.index
result = DataFrame(index=idx)
for idx, col in enumerate(self._val_columns):
for agg in aggs:
result[agg + '_' + col] = col_dfs[idx][agg + '_' + col]
levels = []
codes = []
levels.append(self._val_columns)
levels.append(aggs)
# if the values columns have length == 1, codes is a nested list of
# zeros equal to the size of aggs (sum, min, mean, etc.)
# if the values columns are length>1, codes will monotonically
# increase by 1 for every n values where n is the number of aggs
# [['x,', 'z'], ['sum', 'min']]
# codes == [[0, 1], [0, 1]]
first_codes = [len(aggs) * [d*1] for d in range(len(
self._val_columns))]
codes.append([item for sublist in first_codes for item in sublist])
codes.append(len(self._val_columns) * [0, 1])
result.columns = MultiIndex(levels, codes)
return result
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
