Add first and last method to IndexedFrame
#9710
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
|
|
@@ -3,9 +3,10 @@ | |
|
|
||
| from __future__ import annotations | ||
|
|
||
| import operator | ||
| import warnings | ||
| from collections import abc | ||
| from typing import Callable, Type, TypeVar | ||
| from uuid import uuid4 | ||
|
|
||
| import cupy as cp | ||
|
|
@@ -109,6 +110,7 @@ class IndexedFrame(Frame): | |
| # mypy can't handle bound type variables as class members | ||
| _loc_indexer_type: Type[_LocIndexerClass] # type: ignore | ||
| _iloc_indexer_type: Type[_IlocIndexerClass] # type: ignore | ||
| _index: cudf.core.index.BaseIndex | ||
|
|
||
| def __init__(self, data=None, index=None): | ||
| super().__init__(data=data, index=index) | ||
|
|
@@ -1104,3 +1106,125 @@ def resample( | |
| if isinstance(self, cudf.Series) | ||
| else cudf.core.resample.DataFrameResampler(self, by=by) | ||
| ) | ||
|
|
||
| def _first_or_last( | ||
| self, offset, idx: int, op: Callable, side: str, slice_func: Callable | ||
| ) -> "IndexedFrame": | ||
| """Shared code path for ``first`` and ``last``.""" | ||
| if not isinstance(self._index, cudf.core.index.DatetimeIndex): | ||
| raise TypeError("'first' only supports a DatetimeIndex index.") | ||
| if not isinstance(offset, str): | ||
| raise NotImplementedError( | ||
| f"Unsupported offset type {type(offset)}." | ||
| ) | ||
|
|
||
| if len(self) == 0: | ||
| return self.copy() | ||
|
|
||
| pd_offset = pd.tseries.frequencies.to_offset(offset) | ||
| to_search = op(pd.Timestamp(self._index._column[idx]), pd_offset) | ||
| if ( | ||
| idx == 0 | ||
| and not isinstance(pd_offset, pd.tseries.offsets.Tick) | ||
| and pd_offset.is_on_offset(pd.Timestamp(self._index[0])) | ||
|
There was a problem hiding this comment. does There was a problem hiding this comment. I think pandas In [3]: pd.tseries.frequencies.to_offset('M')
Out[3]: <MonthEnd>
In [4]: pd.tseries.frequencies.to_offset('MS')
Out[4]: <MonthBegin>I believe Like and and for |
||
| ): | ||
| # Special handle is required when the start time of the index | ||
| # is on the end of the offset. See pandas gh29623 for detail. | ||
| to_search = to_search - pd_offset.base | ||
| return self.loc[:to_search] | ||
| end_point = int( | ||
| self._index._column.searchsorted(to_search, side=side)[0] | ||
| ) | ||
| return slice_func(end_point) | ||
|
|
||
| def first(self, offset): | ||
| """Select initial periods of time series data based on a date offset. | ||
|
|
||
| When having a DataFrame with **sorted** dates as index, this function | ||
| can select the first few rows based on a date offset. | ||
|
|
||
| Parameters | ||
| ---------- | ||
| offset: str | ||
| The offset length of the data that will be selected. For intance, | ||
| '1M' will display all rows having their index within the first | ||
| month. | ||
|
|
||
| Returns | ||
| ------- | ||
| Series or DataFrame | ||
| A subset of the caller. | ||
|
|
||
| Raises | ||
| ------ | ||
| TypeError | ||
| If the index is not a ``DatetimeIndex`` | ||
|
|
||
| Examples | ||
| -------- | ||
| >>> i = cudf.date_range('2018-04-09', periods=4, freq='2D') | ||
| >>> ts = cudf.DataFrame({'A': [1, 2, 3, 4]}, index=i) | ||
| >>> ts | ||
| A | ||
| 2018-04-09 1 | ||
| 2018-04-11 2 | ||
| 2018-04-13 3 | ||
| 2018-04-15 4 | ||
| >>> ts.first('3D') | ||
| A | ||
| 2018-04-09 1 | ||
| 2018-04-11 2 | ||
| """ | ||
| return self._first_or_last( | ||
| offset, | ||
| idx=0, | ||
| op=operator.__add__, | ||
| side="left", | ||
| slice_func=lambda i: self.iloc[:i], | ||
| ) | ||
|
|
||
| def last(self, offset): | ||
| """Select final periods of time series data based on a date offset. | ||
|
|
||
| When having a DataFrame with **sorted** dates as index, this function | ||
| can select the last few rows based on a date offset. | ||
|
|
||
| Parameters | ||
| ---------- | ||
| offset: str | ||
| The offset length of the data that will be selected. For instance, | ||
| '3D' will display all rows having their index within the last 3 | ||
| days. | ||
|
|
||
| Returns | ||
| ------- | ||
| Series or DataFrame | ||
| A subset of the caller. | ||
|
|
||
| Raises | ||
| ------ | ||
| TypeError | ||
| If the index is not a ``DatetimeIndex`` | ||
|
|
||
| Examples | ||
| -------- | ||
| >>> i = cudf.date_range('2018-04-09', periods=4, freq='2D') | ||
| >>> ts = cudf.DataFrame({'A': [1, 2, 3, 4]}, index=i) | ||
| >>> ts | ||
| A | ||
| 2018-04-09 1 | ||
| 2018-04-11 2 | ||
| 2018-04-13 3 | ||
| 2018-04-15 4 | ||
| >>> ts.last('3D') | ||
| A | ||
| 2018-04-13 3 | ||
| 2018-04-15 4 | ||
| """ | ||
| return self._first_or_last( | ||
| offset, | ||
| idx=-1, | ||
| op=operator.__sub__, | ||
| side="right", | ||
| slice_func=lambda i: self.iloc[i:], | ||
| ) | ||
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
What does the
opcallable do? and what is the operation being done in this line // what doesto_searchrepr? jwThere was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
If
firstis called, thenopisaddto compute the cut-off date counting from the first date in the column; iflast,opissubto compute the that from the last date.to_searchis the cut-off date. Feel free to request changes if the naming/logic isn't very readable to your taste.